Details of the Researcher

PHOTO

Taro Yamashita
Section
Graduate School of Engineering
Job title
Professor

Research History 3

  • 2021/06 - Present
    Tohoku University

  • 2018/02 - 2021/05
    Nagoya University　Graduate School of Engineering Electronics　Associate professor

  • 2009/06 - 2018/01
    National Institute of Information and Communications Technology

Research Interests 4

  • 量子計算

  • 光子検出器

  • スピントロニクス

  • 超伝導

Research Areas 2

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Electronic devices and equipment /

  • Natural sciences / Magnetism, superconductivity, and strongly correlated systems /

Awards 5

  1. 第66回前島密賞

    2021/03　公益財団法人通信文化協会　超伝導ナノワイヤを用いた単一光子検出器の開発

  2. 第21回超伝導科学技術賞

    2017/04　超伝導科学技術研究会　超伝導ナノワイヤ単一光子検出器システムの開発

  3. 文部科学大臣表彰 若手科学者賞

    2017/04　文部科学省　超伝導光子検出器の高度化とその量子及び生命科学応用の研究

  4. 日本学術振興会 超伝導エレクトロニクス第146委員会賞

    2016/04　日本学術振興会　超伝導エレクトロニクス分野における秀れた研究成果

  5. 応用物理学会講演奨励賞

    2012/03　応用物理学会　超伝導単一光子検出器における揺らぎとダークカウント起源

Papers 152

  1. Loss Mechanisms of Epitaxial NbN Coplanar Waveguide Resonators on an MgO Substrate

    Kohki Watanabe, Hiroki Kutsuma, Sunmi Kim, Taro Yamashita

    IEEE Transactions on Applied Superconductivity　35　(5)　1-5　2025/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2024.3513276 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  2. Superconducting flux qubit with ferromagnetic Josephson π-junction operating at zero magnetic field

    Sunmi Kim, Leonid V. Abdurakhimov, Duong Pham, Wei Qiu, Hirotaka Terai, Sahel Ashhab, Shiro Saito, Taro Yamashita, Kouichi Semba

    Communications Materials　5　(1)　2024/10/11

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s43246-024-00659-1 　

    eISSN： 2662-4443

  3. Self-Shunted Superconducting Flux Qubit

    Tokunoshin Uchida, Hiroki Kutsuma, Taro Yamashita

    IEEE Transactions on Applied Superconductivity　34　(7)　1-8　2024/10

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2024.3419905 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  4. Microwave-multiplexed qubit controller using adiabatic superconductor logic

    Naoki Takeuchi, Taiki Yamae, Taro Yamashita, Tsuyoshi Yamamoto, Nobuyuki Yoshikawa

    npj Quantum Information　10　(1)　2024/06/03

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41534-024-00849-2 　

    eISSN： 2056-6387

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    Abstract Cryogenic qubit controllers (QCs) are the key to build large-scale superconducting quantum processors. However, developing scalable QCs is challenging because the cooling power of a dilution refrigerator is too small (~10 μW at ~10 mK) to operate conventional logic families, such as complementary metal-oxide-semiconductor logic and superconducting single-flux-quantum logic, near qubits. Here we report on a scalable QC using an ultra-low-power superconductor logic family, namely adiabatic quantum-flux-parametron (AQFP) logic. The AQFP-based QC, referred to as the AQFP-multiplexed QC (AQFP-mux QC), produces multi-tone microwave signals for qubit control with an extremely small power dissipation of 81.8 pW per qubit. Furthermore, the AQFP-mux QC adopts microwave multiplexing to reduce the number of coaxial cables for operating the entire system. As a proof of concept, we demonstrate an AQFP-mux QC chip that produces microwave signals at two output ports through microwave multiplexing and demultiplexing. Experimental results show an output power of approximately −80 dBm and on/off ratio of ~40 dB at each output port. Basic mixing operation is also demonstrated by observing sideband signals.

  5. Numerical Study on Physical Reservoir Computing With Josephson Junctions

    Kohki Watanabe, Yoshinao Mizugaki, Satoshi Moriya, Hideaki Yamamoto, Taro Yamashita, Shigeo Sato

    IEEE Transactions on Applied Superconductivity　34　(3)　1-4　2024/05

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2024.3350576 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  6. Investigation of timing margin in single-flux-quantum 4 bit adders for increasing clock frequency of gate-level-pipelined circuits

    Ikki Nagaoka, Tomoki Nakano, Ryota Kashima, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    Applied Physics Express　17　(5)　054501-054501　2024/05/01

    Publisher: IOP Publishing

    DOI： 10.35848/1882-0786/ad46e5 　

    ISSN： 1882-0778

    eISSN： 1882-0786

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    Abstract This study investigates the timing margin required to handle fluctuations and variations in superconductor single-flux-quantum gate-level-pipelined adders; a smaller timing margin would improve the clock frequencies of gate-level-pipelined circuits. To evaluate timing margins, we demonstrated three 4 bit adders with 50-, 75-, and 100 GHz target clock frequencies using a 1.0 μm process. We estimated that the required timing margin of the adders was 2.1 ps. This indicates that previously reported gate-level-pipelined circuits operating at 30–60 GHz could operate at higher clock frequencies by reducing the timing margins.

  7. NbN-based tunnel-type π-junctions for low-power half-flux-quantum circuits

    Duong Pham, Feng Li, Kenjiro Oba, Yuto Takeshita, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    Superconductor Science and Technology　37　(5)　055004-055004　2024/04/17

    Publisher: IOP Publishing

    DOI： 10.1088/1361-6668/ad3c9c 　

    ISSN： 0953-2048

    eISSN： 1361-6668

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    Abstract We have developed half-flux-quantum (HFQ) circuits using all-π-junctions formed from an NbN/AlN/PdNi/NbN (SIFS) structure. The circuits were fabricated using a novel process that incorporated a ground plane on top of the chip, enabling the epitaxial growth of NbN-based junctions from the substrate. The π-state of the junctions was demonstrated through a HFQ shift. Notably, these π-junctions exhibited self-overdamped current-voltage characteristics, enabling them to function as switching components without the need for shunt resistors. The elimination of shunt resistors and the high sheet inductance of NbN are expected to enhance the density of HFQ circuits. To evaluate the performance and power consumption of the all-π-junctions HFQ circuits, we designed and fabricated an HFQ toggle flip-flop (HFQ-TFF) circuit utilizing π-π-π SQUIDs as the fundamental components. Our findings reveal that the NbN-based HFQ-TFF circuit correctly operates as a frequency divider while consuming only around 30% of the power compared to single-flux-quantum TFF (SFQ-TFF) circuits. These results suggest that the HFQ circuit using SIFS-π-junctions has promising potential for integrated circuits requiring low-power consumption at cryogenic temperatures, such as qubit control.

  8. NbN-based half-flux-quantum element for integration with superconducting qubits

    Naoki Takeuchi, Mikiya Naruse, Shigeyuki Miyajima, Duong Pham, Hirotaka Terai, Masamitsu Tanaka, Taro Yamashita

    Applied Physics Letters　124　(15)　2024/04/08

    Publisher: AIP Publishing

    DOI： 10.1063/5.0203046 　

    ISSN： 0003-6951

    eISSN： 1077-3118

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    Half-flux-quantum (HFQ) logic is a superconductor logic family comprising conventional Josephson junctions (0-JJs) and π Josephson junctions (π-JJs). The energy scale of HFQ logic can be flexibly reduced by phase shifts owing to π-JJs; thus, HFQ circuits are a promising building block for qubit interface circuits. In this study, we demonstrate an NbN-based HFQ circuit element compatible with NbN-based superconducting qubits for all-NbN monolithic integration of qubits and HFQ circuits. The use of NbN is beneficial for both qubits and HFQ circuits owing to its high-quality junctions and high kinetic inductance. First, we developed a prototype of an NbN-based 0-JJ/π-JJ hybrid fabrication process for designing HFQ circuits. We evaluated 0-JJs and π-JJs fabricated through the hybrid process, which demonstrated that the 0-JJs had a small deviation with regard to critical current density and the π-JJs had a sufficiently high critical current density to work as π phase shifters. Furthermore, we fabricated an HFQ superconducting quantum interference device, which is one of the most fundamental elements in HFQ circuits, and observed clear HFQ-period modulation in the magnetic flux dependence of the maximum current at 4.2 K.

  9. Control Circuits for Superconducting Qubits: Invited Peer-reviewed

    Naoki TAKEUCHI, Hiroshi FUKETA, Taro YAMASHITA, Tsuyoshi YAMAMOTO

    TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan)　59　(2)　71-79　2024/03/20

    Publisher: Cryogenic Association of Japan

    DOI： 10.2221/jcsj.59.71 　

    ISSN： 0389-2441

    eISSN： 1880-0408

  10. Energy efficient half-flux-quantum circuit aiming at milli-kelvin stage operation

    Feng Li, Duong Pham, Yuto Takeshita, Masayuki Higashi, Taro Yamashita, Masamitsu Tanaka, Akira Fujimaki

    Superconductor Science and Technology　36　(10)　105006-105006　2023/08/25

    Publisher: IOP Publishing

    DOI： 10.1088/1361-6668/acf0f2 　

    ISSN： 0953-2048

    eISSN： 1361-6668

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    Abstract Half-flux-quantum (HFQ) circuits are based on 0–π superconducting quantum interference devices (SQUIDs) and is one of the energy-efficient superconductor digital circuits. The bit energy is determined by the critical current Icn of 0–π SQUID, which can be easily tuned with the loop inductance and junction critical current. In this work, an alternative π–π–π SQUID is adopted to demonstrate HFQ circuits to simplify the fabrication process and enhance circuit energy efficiency. The properties of superconductor/ferromagnet/insulator/superconductor Josephson junctions (π-JJs) are measured with temperature dependence from 4.2 K down to 10 mK. HFQ toggle flip-flops (TFFs) are successfully demonstrated at frequencies of up to 6.7 GHz and 44.5 GHz at temperatures of 4.2 K and 10 mK, respectively. Comparing the HFQ TFF with its rapid single-flux quantum counterpart under the same fabrication process, it is anticipated that the HFQ TFF will exhibit approximately 70% reduction in both static and dynamic energy dissipation. This research establishes the foundation for developing cryogenic interface control and readout circuits for large-scale quantum computing in the future.

  11. Analysis of the Effect of 0-π SQUIDs for Enhancing Mutual Coupling

    Masayuki Higashi, Yuto Takeshita, Kento Kato, Hinata Fujisawa, Feng Li, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　33　(5)　1-5　2023/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2023.3249657 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  12. Fabrication Process for Monolithic Integration of a Nitride Superconductor-Based Superconducting Qubit with a Single Flux Quantum Control Circuit

    Shigeyuki Miyajima, Taro Yamashita, Masamitsu Tanaka, Naoki Takeuchi, Kunihiro Inomata, Hirotaka Terai

    IEEE Transactions on Applied Superconductivity　33　(5)　1-4　2023/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2023.3241270 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  13. Lowering Latency in a High-Speed Gate-Level-Pipelined Single Flux Quantum Datapath Using an Interleaved Register File

    Ryota Kashima, Ikki Nagaoka, Tomoki Nakano, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　33　(5)　1-6　2023/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2023.3249131 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  14. 50-GFLOPS Floating-Point Adder and Multiplier Using Gate-Level-Pipelined Single-Flux-Quantum Logic With Frequency-Increased Clock Distribution

    Ikki Nagaoka, Ryota Kashima, Masamitsu Tanaka, Satoshi Kawakami, Teruo Tanimoto, Taro Yamashita, Koji Inoue, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　33　(4)　1-11　2023/06

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2023.3250614 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  15. A High-Throughput Multiply-Accumulate Unit With Long Feedback Loop Using Low-Voltage Rapid Single-Flux Quantum Circuits

    Ikki Nagaoka, Ryota Kashima, Koki Ishida, Masamitsu Tanaka, Taro Yamashita, Takatsugu Ono, Koji Inoue, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　33　(3)　1-8　2023/04

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2023.3239329 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  16. Direct observations of pi-leaps of superconducting phase differences in pi-junction-based SQUIDs

    Yuto Takeshita, Feng Li, Masayuki Higashi, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    SUPERCONDUCTOR SCIENCE & TECHNOLOGY　36　(4)　2023/04

    DOI： 10.1088/1361-6668/acb38d 　

    ISSN： 0953-2048

    eISSN： 1361-6668

  17. Weak spin-flip scattering in Pd89Ni11 interlayer of NbN-based ferromagnetic Josephson junctions Peer-reviewed

    Duong Pham, Riku Sugimoto, Kenjiro Oba, Yuto Takeshita, Feng Li, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    Scientific Reports　12　(1)　2022/12

    DOI： 10.1038/s41598-022-10967-6 　

    ISSN： 2045-2322

    eISSN： 2045-2322

  18. A 57.2GHz 11.2mW 8-bit General Purpose Superconductor Microprocessor with Dual-Clocking Scheme

    Ikki Nagaoka, Ryota Kashima, Tomoki Nakano, Masamitsu Tanaka, Taro Yamashita, Koji Inoue, Akira Fujimaki

    2022 IEEE Asian Solid-State Circuits Conference (A-SSCC)　2022/11/06

    Publisher: IEEE

    DOI： 10.1109/a-sscc56115.2022.9980802 　

  19. Enhanced coherence of all-nitride superconducting qubits epitaxially grown on silicon substrate

    Sunmi Kim, Hirotaka Terai, Taro Yamashita, Wei Qiu, Tomoko Fuse, Fumiki Yoshihara, Sahel Ashhab, Kunihiro Inomata, Kouichi Semba

    Communications Materials　2　(1)　2021/12

    DOI： 10.1038/s43246-021-00204-4 　

    eISSN： 2662-4443

  20. Magnetic Josephson Junctions: New Phenomena and Physics with Diluted Alloy, Conventional Ferromagnet, and Multilayer Barriers

    Taro YAMASHITA

    IEICE Transactions on Electronics　E104.C　(9)　422-428　2021/09/01

    DOI： 10.1587/transele.2020sui0004 　

    ISSN： 0916-8524

    eISSN： 1745-1353

  21. Demonstration of Interface Circuits Between Half- and Single- Flux- Quantum Circuits

    Daiki Hasegawa, Yuto Takeshita, Feng Li, Kyosuke Sano, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　31　(5)　1-4　2021/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2021.3072846 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  22. High-Speed Memory Driven by SFQ Pulses Based on 0-π SQUID

    Yuto Takeshita, Feng Li, Daiki Hasegawa, Kyosuke Sano, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　31　(5)　1-6　2021/08

    DOI： 10.1109/tasc.2021.3060351 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  23. 64-GHz Datapath Demonstration for Bit-Parallel SFQ Microprocessors Based on a Gate-Level-Pipeline Structure

    Ryota Kashima, Ikki Nagaoka, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　31　(5)　1-6　2021/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2021.3061353 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  24. Investigation of Timing Parameters in Single-Flux-Quantum Circuits Using Low Critical-Current Junctions and Low Bias Voltages

    Manami Kuniyoshi, Ken Murase, Ikki Nagaoka, Kyosuke Sano, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　31　(5)　1-5　2021/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2021.3067827 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  25. Demonstration of a 52-GHz Bit-Parallel Multiplier Using Low-Voltage Rapid Single-Flux-Quantum Logic

    Ikki Nagaoka, Koki Ishida, Masamitsu Tanaka, Kyosuke Sano, Taro Yamashita, Takatsugu Ono, Koji Inoue, Akira Fujimaki

    IEEE Transactions on Applied Superconductivity　31　(5)　1-5　2021/08

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tasc.2021.3071996 　

    ISSN： 1051-8223

    eISSN： 1558-2515 2378-7074

  26. Low-power high-speed half-flux-quantum circuits driven by low bias voltages

    Feng Li, Yuto Takeshita, Daiki Hasegawa, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    Superconductor Science and Technology　34　(2)　025013-025013　2021/02/01

    Publisher: IOP Publishing

    DOI： 10.1088/1361-6668/abcaac 　

    ISSN： 0953-2048

    eISSN： 1361-6668

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    Abstract Half-flux-quantum (HFQ) circuits store and propagate half-flux quanta. The basic circuit element is a 0-π SQUID, which is a superconducting quantum interference device with a conventional Josephson junction (0-junction) and a π-shifted ferromagnetic junction (π-junction). A 0-π SQUID achieves a small critical current in the absence of an external magnetic field, thus reducing power consumption. It is easy to set up 0-0-π SQUIDs with two 0-junctions and a π-junction which serves as a π phase-shifter. We simulated 0-0-π SQUID-based HFQ circuits driven by low bias voltages, referred to as LV-HFQ circuits. In these circuits, shunt resistors are not required for switching junctions because there is no hysteresis in the current–voltage characteristics of 0-0-π SQUIDs. We estimated the power consumption and maximum operating frequency of an HFQ Josephson transmission line based on 0-0-π SQUIDs. When operating at 43.5 GHz, the power dissipation of a single element composed of a 0-0-π SQUID and a bias resistor fell to about 0.165 nW when biased at 60 μV. The LV-HFQ circuit is potentially more power-efficient than all other currently available superconducting logic circuits.

  27. π phase shifter based on NbN-based ferromagnetic Josephson junction on a silicon substrate

    Taro Yamashita, Sunmi Kim, Haruki Kato, Wei Qiu, Kouichi Semba, Akira Fujimaki, Hirotaka Terai

    Scientific Reports　10　(1)　2020/12

    DOI： 10.1038/s41598-020-70766-9 　

    ISSN： 2045-2322

    eISSN： 2045-2322

  28. Robust entanglement distribution via telecom fibre assisted by an asynchronous counter-propagating laser light Peer-reviewed

    Koichiro Miyanishi, Yoshiaki Tsujimoto, Rikizo Ikuta, Shigehito Miki, Masahiro Yabuno, Taro Yamashita, Hirotaka Terai, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto

    npj Quantum Information　6　(1)　2020/12

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41534-020-0273-5 　

    eISSN： 2056-6387

  29. Development and Evaluation of Superconducting Nanowire Single-Photon Detectors for 900-1100 nm Photon Detection

    Fumihiro CHINA, Shigehito MIKI, Masahiro YABUNO, Taro YAMASHITA, Hirotaka TERAI

    IEICE Transactions on Electronics　E103.C　(5)　212-215　2020/05/01

    Publisher: Institute of Electronics, Information and Communications Engineers (IEICE)

    DOI： 10.1587/transele.2019ses0001 　

    ISSN： 0916-8524

    eISSN： 1745-1353

  30. Boosting the secret key rate in a shared quantum and classical fibre communication system Peer-reviewed

    D. Bacco, B. D. Lio, D. Cozzolino, F. D. Ros, X. Guo, Y. Ding, Y. Sasaki, K. Aikawa, S. Miki, H. Terai, T. Yamashita, J. S. Neergaard-Nielsen, M. Galili, K. Rottwitt, U. L. Andersen, T. Morioka, L. K. Oxenløwe

    Communications Physics　2　140　2019/11/11

    DOI： 10.1038/s42005-019-0238-1 　

    ISSN： 2399-3650

  31. Timing Jitter Characterization of the SFQ Coincidence Circuit by Optically Time-Controlled Signals From SSPDs Peer-reviewed

    Miki Shigehito, Miyajima Shigeyuki, Yabuno Masahiro, Yamashita Taro, Yamamoto Takashi, Imoto Nobuyuki, Ikuta Rikizo, Kirkwood Robert A, Hadfield Robert H, Terai Hirotaka

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY　29　(5)　2019/08

    DOI： 10.1109/TASC.2019.2906258 　

    ISSN： 1051-8223

    eISSN： 1558-2515

  32. Demonstration of a Superconducting Nanowire Single-Photon Detector using Adiabatic Quantum-Flux-Parametron Logic in a 0.1-W Gifford-McMahon Cryocooler

    Naoki Takeuchi, Taro Yamashita, Shigeyuki Miyajima, Shigehito Miki, Nobuyuki Yoshikawa, Hirotaka Terai

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY　29　(5)　2019/08

    DOI： 10.1109/TASC.2019.2902771 　

    ISSN： 1051-8223

    eISSN： 1558-2515

  33. Demonstration of an Energy-Efficient, Gate-Level-Pipelined 100 TOPS/W Arithmetic Logic Unit Based on Low-Voltage Rapid Single-Flux-Quantum Logic

    Ikki Nagaoka, Masamitsu Tanaka, Kyosuke Sano, Taro Yamashita, Akira Fujimaki, Koji Inoue

    ISEC 2019 - International Superconductive Electronics Conference　2019/07/01

    Publisher: Institute of Electrical and Electronics Engineers Inc.

    DOI： 10.1109/ISEC46533.2019.8990905 　

  34. Fundamental study on the nanocryotron properties by the numerical calculation Peer-reviewed

    M. Inoue, K. Izaki, Y. Goto, K. Sano, T. Yamashita, M. Tanaka, A. Fujimaki

    IEEE Transactions on Applied Superconductivity　29　2019/03/12

  35. Enhanced Optics for Time-Resolved Singlet Oxygen Luminescence Detection Peer-reviewed

    Konstantinos Tsimvrakidis,Nathan R. Gemmell, Kleanthis Erotokritou, Shigehito Miki, Masahiro Yabuno, Taro Yamashita, Hirotaka Terai, Robert H. Hadfield

    IEEE Journal of Selected Topics in Quantum Electronics　25　(1)　Article Sequence Number: 7000107　2019

    DOI： 10.1109/JSTQE.2018.2836962 　

    ISSN： 1077-260X

    eISSN： 1558-4542

  36. Adiabatic quantum-flux-parametron with π Josephson junctions Peer-reviewed

    K. Arai, N. Takeuchi, T. Yamashita, N. Yoshikawa

    Journal of Applied Physics　125　(9)　093901 -1-7　2019

    DOI： 10.1063/1.5080467 　

  37. High-fidelity entanglement swapping and generation of three-qubit GHz state using asynchronous telecom photon pair sources

    Yoshiaki Tsujimoto, Motoki Tanaka, Nobuo Iwasaki, Rikizo Ikuta, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto

    Scientific Reports　8　(1)　2018/12/01

    DOI： 10.1038/s41598-018-19738-8 　

    ISSN： 2045-2322

  38. Polarization insensitive frequency conversion for an atom-photon entanglement distribution via a telecom network

    Rikizo Ikuta, Toshiki Kobayashi, Tetsuo Kawakami, Shigehito Miki, Masahiro Yabuno, Taro Yamashita, Hirotaka Terai, Masato Koashi, Tetsuya Mukai, Takashi Yamamoto, Nobuyuki Imoto

    Nature Communications　9　(1)　2018/12/01

    Publisher: Nature Publishing Group

    DOI： 10.1038/s41467-018-04338-x 　

    ISSN： 2041-1723

  39. Phase shift and control in superconducting hybrid structures

    Taro Yamashita

    IEICE Transactions on Electronics　E101C　(5)　378-384　2018/05/01

    DOI： 10.1587/transele.E101.C.378 　

    ISSN： 1745-1353 0916-8524

  40. Record-high secret key rate for joint classical and quantum transmission over a 37-core fiber

    Beatrice Da Lio, Davide Bacco, Daniele Cozzolino, Francesco Da Ros, Xueshi Guo, Yunhong Ding, Yusuke Sasaki, Kazuhiko Aikawa, Shigehito Miki, Hirotaka Terai, Taro Yamashita, Jonas S. Neergaard-Nielsen, Michael Galili, Karsten Rottwitt, Ulrik L. Andersen, Leif K. Oxenlowe, Toshio Morioka

    2018 IEEE PHOTONICS CONFERENCE (IPC)　2018

    ISSN： 2374-0140

  41. Superconducting nanowire single-photon detectors for future optical communications Peer-reviewed

    Hirotaka Terai, Shigehito Miki, Taro Yamashita, Shigeyuki Miyajima, Masahiro Yabuno

    Optics InfoBase Conference Papers　2018　2018

    DOI： 10.1364/OFC.2018.M3G.4 　

  42. Superconducting coincidence photon detector with short timing jitter Peer-reviewed

    S. Miki, S. Miyajima, M. Yabuno, T. Yamashita, T. Yamamoto, N. Imoto, R. Ikuta, R.A. Kirkwood, R.H. Hadfield, H. Terai

    Applied Physics Letters　112　(26)　262601 -1-5　2018

    DOI： 10.1063/1.5037254 　

  43. High-time-resolved 64-channel single-flux quantum-based address encoder integrated with a multi-pixel superconducting nanowire single-photon detector Peer-reviewed

    Shigeyuki Miyajima, Masahiro Yabuno, Shigehito Miki, Taro Yamashita, Hirotaka Terai

    Optics Express　26　(22)　29045-29054-29054　2018

    DOI： 10.1364/OE.26.029045 　

    ISSN： 1094-4087

  44. Broadening the IF Band of a THz Hot-Electron Bolometer Mixer by Using a Magnetic Thin Film Peer-reviewed

    A. Kawakami, Y. Irimajiri, T. Yamashita, S. Ochiai, Y. Uzawa

    IEEE Transactions on Terahertz Science and Technology　8　(6)　647-653-653　2018

    DOI： 10.1109/TTHZ.2018.2874355 　

    ISSN： 2156-342X

  45. 大規模量子計算に向けた超伝導量子回路の作製技術 Peer-reviewed

    寺井弘高, 丘偉, 山下太郎

    低温工学　53　(5)　295-305　2018

    DOI： 10.2221/jcsj.53.295 　

  46. Adiabatic quantum-flux-parametron interface for the readout of superconducting nanowire single-photon detectors

    Naoki Takeuchi, Taro Yamashita, Shigeyuki Miyajima, Shigehito Miki, Nobuyuki Yoshikawa, Hirotaka Terai

    Optics Express　25　(26)　32650-32658　2017/12/25

    DOI： 10.1364/OE.25.032650 　

    ISSN： 1094-4087

  47. Timing discriminator based on single-fluxquantum circuit toward high time-resolved photon detection

    Shigeyuki Miyajima, Shigehito Miki, Masahiro Yabuno, Taro Yamashita, Hirotaka Terai

    SUPERCONDUCTOR SCIENCE & TECHNOLOGY　30　(12)　2017/12

    DOI： 10.1088/1361-6668/aa926e 　

    ISSN： 0953-2048

    eISSN： 1361-6668

  48. NbN-Based Ferromagnetic 0 and pi Josephson Junctions

    Taro Yamashita, Akira Kawakami, Hirotaka Terai

    PHYSICAL REVIEW APPLIED　8　(5)　2017/11

    DOI： 10.1103/PhysRevApplied.8.054028 　

    ISSN： 2331-7019

  49. Silicon photonic processor of two-qubit entangling quantum logic Peer-reviewed

    R. Santagati, J. W. Silverstone, M. J. Strain, M. Sorel, S. Miki, T. Yamashita, M. Fujiwara, M. Sasaki, H. Terai, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, J. L. O'Brien, M. G. Thompson

    Journal of Optics (United Kingdom)　19　(11)　2017/10/17

    Publisher: Institute of Physics Publishing

    DOI： 10.1088/2040-8986/aa8d56 　

    ISSN： 2040-8986 2040-8978

  50. Mach-Zehnder interferometer using frequency-domain beamsplitter

    Toshiki Kobayashi, Daisuke Yamazaki, Kenichiro Matsuki, Rikizo Ikuta, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto

    OPTICS EXPRESS　25　(10)　12052-12060　2017/05

    DOI： 10.1364/OE.25.012052 　

    ISSN： 1094-4087

  51. High visibility Hong-Ou-Mandel interference via a time-resolved coincidence measurement

    Yoshiaki Tsujimoto, Yukihiro Sugiura, Motoki Tanaka, Rikizo Ikuta, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Nobuyuki Imoto

    OPTICS EXPRESS　25　(11)　12069-12080　2017/05

    DOI： 10.1364/OE.25.012069 　

    ISSN： 1094-4087

  52. Recent Progress and Application of Superconducting Nanowire Single-Photon Detectors

    Taro Yamashita, Shigehito Miki, Hirotaka Terai

    IEICE TRANSACTIONS ON ELECTRONICS　E100C　(3)　274-282　2017/03

    DOI： 10.1587/transele.E100.C.274 　

    ISSN： 1745-1353

  53. Stable, high-performance operation of a fiber-coupled superconducting nanowire avalanche photon detector

    Shigehito Miki, Masahiro Yabuno, Taro Yamashita, Hirotaka Terai

    OPTICS EXPRESS　25　(6)　6796-6804　2017/03

    DOI： 10.1364/OE.25.006796 　

    ISSN： 1094-4087

  54. Chip-based quantum key distribution

    P. Sibson, C. Erven, M. Godfrey, S. Miki, T. Yamashita, M. Fujiwara, M. Sasaki, H. Terai, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, J. L. O'Brien, M. G. Thompson

    NATURE COMMUNICATIONS　8　2017/02

    DOI： 10.1038/ncomms13984 　

    ISSN： 2041-1723

  55. High-extinction ratio integrated photonic filters for silicon quantum photonics

    Mateusz Piekarek, Damien Bonneau, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    OPTICS LETTERS　42　(4)　815-818　2017/02

    DOI： 10.1364/OL.42.000815 　

    ISSN： 0146-9592

    eISSN： 1539-4794

  56. Cryogenic Signal Processing Using Single-flux-quantum Circuit for High Performance Multi-pixel Superconducting Nanowire Single-photon Detectors

    TERAI Hirotaka, MIKI Shigehito, YAMASHITA Taro, MIYAJIMA Shigeyuki, YABUNO Masahiro

    TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan)　52　(5)　340-348　2017

    Publisher: CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

    DOI： 10.2221/jcsj.52.340 　

    ISSN： 0389-2441

    More details Close

    <p>Superconducting nanowire single-photon detectors (SSPDs) with a system detection efficiency (SDE) of over 80% are now commercially available and being used in compact Gifford-McMahon refrigerators. However, not only high SDE, but also total performance including a low dark count rate, high maximum count rate and/or low timing jitter are important for many applications. A multi-pixel SSPD combined with signal processing using a single-flux-quantum (SFQ) circuit is a very promising approach to improve the system performance of SSPDs. In this review, we introduce our recent activities on cryogenic signal processing using SFQ circuits to realize high-performance multi-pixel SSPDs.<tt> </tt></p>

  57. Detection-dependent six-photon Holland-Burnett state interference

    Rui-Bo Jin, Mikio Fujiwara, Ryosuke Shimizu, Robert J. Collins, Gerald S. Buller, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Masahiro Takeoka, Masahide Sasaki

    SCIENTIFIC REPORTS　6　2016/11

    DOI： 10.1038/srep36914 　

    ISSN： 2045-2322

  58. Heralded single excitation of atomic ensemble via solid-state-based telecom photon detection

    Rikizo Ikuta, Toshiki Kobayashi, Kenichiro Matsuki, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Takashi Yamamoto, Masato Koashi, Tetsuya Mukai, Nobuyuki Imoto

    OPTICA　3　(11)　1279-1284　2016/11

    DOI： 10.1364/OPTICA.3.001279 　

    ISSN： 2334-2536

  59. Quantum teleportation with independent sources and prior entanglement distribution over a network

    Qi-Chao Sun, Ya-Li Mao, Si-Jing Chen, Wei Zhang, Yang-Fan Jiang, Yan-Bao Zhang, Wei-Jun Zhang, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Xiao Jiang, Teng-Yun Chen, Li-Xing You, Xian-Feng Chen, Zhen Wang, Jing-Yun Fan, Qiang Zhang, Jian-Wei Pan

    NATURE PHOTONICS　10　(10)　671-675　2016/10

    DOI： 10.1038/NPHOTON.2016.179 　

    ISSN： 1749-4885

    eISSN： 1749-4893

  60. Superconducting nanowire single-photon detectors with non-periodic dielectric multilayers

    Taro Yamashita, Kentaro Waki, Shigehito Miki, Robert A. Kirkwood, Robert H. Hadfield, Hirotaka Terai

    SCIENTIFIC REPORTS　6　2016/10

    DOI： 10.1038/srep35240 　

    ISSN： 2045-2322

  61. Single-photon emission at 1.5 mu m from an InAs/InP quantum dot with highly suppressed multi-photon emission probabilities

    T. Miyazawa, K. Takemoto, Y. Nambu, S. Miki, T. Yamashita, H. Terai, M. Fujiwara, M. Sasaki, Y. Sakuma, M. Takatsu, T. Yamamoto, Y. Arakawa

    APPLIED PHYSICS LETTERS　109　(13)　2016/09

    DOI： 10.1063/1.4961888 　

    ISSN： 0003-6951

    eISSN： 1077-3118

  62. Simple method of generating and distributing frequency-entangled qudits Peer-reviewed

    Rui-Bo Jin, Ryosuke Shimizu, Mikio Fujiwara, Masahiro Takeoka, Ryota Wakabayashi, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Thomas Gerrits, Masahide Sasaki

    Quantum Science and Technology　1　(1)　2016/08/01

    Publisher: Institute of Physics Publishing

    DOI： 10.1088/2058-9565/1/1/015004 　

    ISSN： 2058-9565

  63. Frequency-domain Hong-Ou-Mandel interference

    Toshiki Kobayashi, Rikizo Ikuta, Shuto Yasui, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto

    NATURE PHOTONICS　10　(7)　441-+　2016/07

    DOI： 10.1038/nphoton.2016.74 　

    ISSN： 1749-4885

    eISSN： 1749-4893

  64. Chip-to-chip quantum photonic interconnect by path-polarization interconversion

    Jianwei Wang, Damien Bonneau, Matteo Villa, Joshua W. Silverstone, Raffaele Santagati, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    OPTICA　3　(4)　407-413　2016/04

    DOI： 10.1364/OPTICA.3.000407 　

    ISSN： 2334-2536

  65. 21pBJ-1 High fidelity entanglement swapping via a time-resolved coincidence measurement

    Tsujimoto Yoshiaki, Sugiura Yukihiro, Tanaka Motoki, Ikuta Rikizo, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Yamamoto Takashi, Koashi Masato, Imoto Nobuyuki

    Meeting Abstracts of the Physical Society of Japan　71　743-743　2016

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.71.1.0_743 　

    ISSN： 2189-079X

  66. Comparison of Photon Pair Generation in a-Si:H and c-Si Microring Resonators

    E. Hemsley, D. Bonneau, G. Sinclair, J. Pelc, R. Beausoleil, S. Miki, T. Yamashita, M. Fujiwara, M. Sasaki, H. Terai, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, J. L. O'Brien, M. G. Thompson

    2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2016

    ISSN： 2160-9020

  67. Passive High-Extinction Integrated Photonic Filters for Silicon Quantum Photonics

    Mateusz Piekarek, Damien Bonneau, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2016

    ISSN： 2160-9020

  68. Ground state solver on a silicon quantum photonic chip

    R. Santagati, J. Wang, S. Paesani, A. A. Gentile, D. Bonneau, J. W. Silverstone, S. Morley-Short, X. Zhou, P. J. Shadbolt, N. Wiebe, S. Miki, T. Yamashita, M. Fujiwara, M. Sasaki, H. Terai, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, D. Tew, J. L. O'Brien, M. G. Thompson

    2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2016

    ISSN： 2160-9020

  69. Rotational diffusion measurements using polarization-dependent fluorescence correlation spectroscopy based on superconducting nanowire single-photon detector

    Johtaro Yamamoto, Makoto Oura, Taro Yamashita, Shigehito Miki, Takashi Jin, Tokuko Haraguchi, Yasushi Hiraoka, Hirotaka Terai, Masataka Kinjo

    OPTICS EXPRESS　23　(25)　32633-32642　2015/12

    DOI： 10.1364/OE.23.032633 　

    ISSN： 1094-4087

  70. Spectrally resolved Hong-Ou-Mandel interference between independent photon sources

    Rui-Bo Jin, Thomas Gerrits, Mikio Fujiwara, Ryota Wakabayashi, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Ryosuke Shimizu, Masahiro Takeoka, Masahide Sasaki

    OPTICS EXPRESS　23　(22)　28829-28835　2015/11

    DOI： 10.1364/OE.23.028836 　

    ISSN： 1094-4087

  71. Fabrication and Characterization of Superconducting Nanowire Single-Photon Detectors on Si Waveguide Peer-reviewed

    Kentaro Waki, Taro Yamashita, Shin-ichiro Inoue, Shigehito Miki, Hirotaka Terai, Rikizo Ikuta, Takashi Yamamoto, Nobuyuki Imoto

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY　25　(3)　2015/06

    DOI： 10.1109/TASC.2014.2385836 　

    ISSN： 1051-8223

    eISSN： 1558-2515

  72. Low-Energy Optical-to-Electrical Converters Based on Superconducting Nanowire for Single-Flux-Quantum Circuits

    Kemmei Kajino, Shigehito Miki, Taro Yamashita, Hirotaka Terai

    IEICE TRANSACTIONS ON ELECTRONICS　E98C　(3)　227-231　2015/03

    DOI： 10.1587/transele.E98.C.227 　

    ISSN： 1745-1353

  73. Efficient detection of an ultra-bright single-photon source using superconducting nanowire single-photon detectors

    Rui-Bo Jin, Mikio Fujiwara, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang, Kentaro Wakui, Ryosuke Shimizu, Masahide Sasaki

    OPTICS COMMUNICATIONS　336　47-54　2015/02

    DOI： 10.1016/j.optcom.2014.09.051 　

    ISSN： 0030-4018

    eISSN： 1873-0310

  74. Entanglement distribution between integrated silicon photonic chips

    Jianwei Wang, Damien Bonneau, Matteo Villa, Joshua W. Silverstone, Raffaele Santagati, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    Proceedings of Frontiers in Optics 2015, FIO 2015　2015

    Publisher: OSA - The Optical Society

    DOI： 10.1364/fio.2015.fth1d.6 　

  75. Photonic qubit entanglement and processing in silicon waveguides

    Joshua W. Silverstone, Raffaele Santagati, Damien Bonneau, Michael J. Strain, Marc Sorel, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    Integrated Photonics Research, Silicon and Nanophotonics, IPRSN 2015　371　2015

    Publisher: Optical Society of America (OSA)

    DOI： 10.1364/iprsn.2015.is4a.5 　

  76. 17pAC-5 Wavelength conversion of non-classical light emitted from cold rubidium atoms to the telecom band

    Matsuki Kenichiro, Kobayashi Toshiki, Ikuta Rikizo, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Yamamoto Takashi, Koashi Masato, Mukai Tetsuya, Imoto Nobuyuki

    Meeting Abstracts of the Physical Society of Japan　70　525-525　2015

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.70.2.0_525 　

    ISSN： 2189-079X

  77. Error-free Operation of Superconducting Nanowire Optical-to-Electrical Converter Connected with SFQ Circuits

    Kemmei Kajino, Shigehito Miki, Taro Yamashita, Hirotaka Terai

    2015 15TH INTERNATIONAL SUPERCONDUCTIVE ELECTRONICS CONFERENCE (ISEC)　.　2015

  78. Integrated Photonic Devices for Quantum Key Distribution

    Philip Sibson, Mark Godfrey, Chris Erven, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy O'Brien, Mark G. Thompson

    2015 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2015

    ISSN： 2160-9020

  79. Efficient generation of twin photons at telecom wavelengths with 10 GHz repetition-rate-tunable comb laser

    Rui-Bo Jin, Ryosuke Shimizu, Isao Morohashi, Kentaro Wakui, Masahiro Takeoka, Shuro Izumi, Takahide Sakamoto, Mikio Fujiwara, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang, Masahide Sasaki

    2015 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2015

    ISSN： 2160-9020

  80. Fluorescence Correlation Spectroscopy with Visible-wavelength Superconducting Nanowire Single-photon Detector

    Taro Yamashita, Shigehito Miki, Tokuko Haraguchi, Hirotaka Terai, Johtaro Yamamoto, Masataka Kinjo, Yasushi Hiraoka

    2015 15TH INTERNATIONAL SUPERCONDUCTIVE ELECTRONICS CONFERENCE (ISEC)　.　2015

  81. Chip-to-chip quantum entanglement distribution

    J. Wang, M. Villa, D. Bonneau, R. Santagati, J. W. Silverstone, C. Erven, S. Miki, T. Yamashita, M. Fujiwara, M. Sasaki, H. Terai, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, J. L. O'Brien, M. G. Thompson

    2015 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2015

    ISSN： 2160-9020

  82. Characterization of NbTiN-Based Superconducting Nanowire Single-Photon Detectors on Si Waveguide

    Kentaro Waki, Taro Yamashita, Shin-ichiro Inoue, Shigehito Miki, Hirotaka Terai, Rikizo Ikuta, Takashi Yamamoto, Nobuyuki Imoto

    2015 15TH INTERNATIONAL SUPERCONDUCTIVE ELECTRONICS CONFERENCE (ISEC)　25　(3)　2015

    DOI： 10.1109/TASC.2014.2385836 　

    ISSN： 1051-8223

  83. Efficient generation of twin photons at telecom wavelengths with 2.5 GHz repetition-rate-tunable comb laser

    Rui-Bo Jin, Ryosuke Shimizu, Isao Morohashi, Kentaro Wakui, Masahiro Takeoka, Shuro Izumi, Takahide Sakamoto, Mikio Fujiwara, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang, Masahide Sasaki

    SCIENTIFIC REPORTS　4　2014/12

    DOI： 10.1038/srep07468 　

    ISSN： 2045-2322

  84. Fluorescence correlation spectroscopy with visible-wavelength superconducting nanowire single-photon detector

    Taro Yamashita, Dengkuan Liu, Shigehito Miki, Johtaro Yamamoto, Tokuko Haraguchi, Masataka Kinjo, Yasushi Hiraoka, Zhen Wang, Hirotaka Terai

    OPTICS EXPRESS　22　(23)　28783-28789　2014/11

    DOI： 10.1364/OE.22.028783 　

    ISSN： 1094-4087

  85. Multimode fiber-coupled superconducting nanowire single-photon detector with 70% system efficiency at visible wavelength

    Dengkuan Liu, Shigehito Miki, Taro Yamashita, Lixing You, Zhen Wang, Hirotaka Terai

    OPTICS EXPRESS　22　(18)　21167-21174　2014/09

    DOI： 10.1364/OE.22.021167 　

    ISSN： 1094-4087

  86. Review of superconducting nanowire single-photon detector system design options and demonstrated performance

    Eric A. Dauler, Matthew E. Grein, Andrew J. Kerman, Francesco Marsili, Shigehito Miki, Sae Woo Nam, Matthew D. Shaw, Hirotaka Terai, Varun B. Verma, Taro Yamashita

    OPTICAL ENGINEERING　53　(8)　2014/08

    DOI： 10.1117/1.OE.53.8.081907 　

    ISSN： 0091-3286

    eISSN： 1560-2303

  87. Photon pair generation in an amorphous silicon micro-ring resonator

    Hemsley, D. Bonneau, G. Sinclair, J. Pelc, R. Beausoleil, S. Miki, T. Yamashita, M. Fujiwara, M. Sasaki, H. Terai, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, J. L. O'Brien, M. G. Thompson

    Optics InfoBase Conference Papers　2014/07/21

    Publisher: OSA - The Optical Society

  88. Quantum phase estimation algorithm on a reconfigurable silicon photonic chip

    Raffaele Santagati, Joshua W. Silverstone, Michael J. Strain, Marc Sorel, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    Optics InfoBase Conference Papers　2014/07/21

    Publisher: OSA - The Optical Society

  89. Quantum phase estimation algorithm on a reconfigurable silicon photonic chip

    Raffaele Santagati, Joshua W. Silverstone, Michael J. Strain, Marc Sorel, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy L. O'Brien, Mark G. Thompson

    Optics InfoBase Conference Papers　2014/07/21

    Publisher: OSA - The Optical Society

  90. Integrated photonic transmitter and receiver for quantum key distribution

    Philip Sibson, Mark Godfrey, Chris Erven, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy O'Brien, Mark G. Thompson

    Optics InfoBase Conference Papers　2014/07/21

    Publisher: OSA - The Optical Society

  91. Integrated photonic transmitter and receiver for quantum key distribution

    Philip Sibson, Mark Godfrey, Chris Erven, Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Hirotaka Terai, Michael G. Tanner, Chandra M. Natarajan, Robert H. Hadfield, Jeremy O'Brien, Mark G Thompson

    Optics InfoBase Conference Papers　2014/07/21

    Publisher: OSA - The Optical Society

  92. Bayesian quantum phase estimation on an integrated Silicon photonic device Peer-reviewed

    S. Paesani, A. A. Gentile, R. Santagati, J. Wang, N. Wiebe, S. Miki, T. Yamashita, H. Terai, M. Fujiwara, M. Sasaki, M. G. Tanner, C. M. Natarajan, R. H. Hadfield, D. Tew, J. L. O'Brien, M. G. Thompson

    Optics InfoBase Conference Papers　2014/07/21

    Publisher: OSA - The Optical Society

    DOI： 10.1364/FIO.2016.FTu3G.5 　

  93. Observation of Hong-Ou-Mandel interference by using a frequency-domain beamsplitter Peer-reviewed

    T. Kobayashi, R. Ikuta, S. Yasui, S. Miki, T. Yamashita, H. Terai, M. Fujiwara, T. Yamamoto, M. Sasaki, Z. Wang, M. Koashi, N. Imoto

    Optics InfoBase Conference Papers　2014/07/21

  94. Modified E91 protocol demonstration with hybrid entanglement photon source

    Mikio Fujiwara, Ken-ichiro Yoshino, Yoshihiro Nambu, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang, Morio Toyoshima, Akihisa Tomita, Masahide Sasaki

    OPTICS EXPRESS　22　(11)　13616-13624　2014/06

    DOI： 10.1364/OE.22.013616 　

    ISSN： 1094-4087

  95. Frequency down-conversion of 637 nm light to the telecommunication band for non-classical light emitted from NV centers in diamond

    Rikizo Ikuta, Toshiki Kobayashi, Shuto Yasui, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Zhen Wang, Nobuyuki Imoto

    OPTICS EXPRESS　22　(9)　11205-11214　2014/05

    DOI： 10.1364/OE.22.011205 　

    ISSN： 1094-4087

  96. Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelength

    Rui-Bo Jin, Ryosuke Shimizu, Kentaro Wakui, Mikio Fujiwara, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang, Masahide Sasaki

    OPTICS EXPRESS　22　(10)　11498-11507　2014/05

    DOI： 10.1364/OE.22.011498 　

    ISSN： 1094-4087

  97. A 64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detection

    Shigehito Miki, Taro Yamashita, Zhen Wang, Hirotaka Terai

    OPTICS EXPRESS　22　(7)　7811-7820　2014/04

    DOI： 10.1364/OE.22.007811 　

    ISSN： 1094-4087

  98. Pulsed Sagnac polarization-entangled photonsource with a PPKTP crystal at telecom wavelength

    Rui-Bo Jin, Ryosuke Shimizu, KentaroWakui, Mikio Fujiwara, Taro Yamashita, S. Terai, Shigehito Miki Hirotaka, Zhen Wang, Masahide Sasaki

    Optics InfoBase Conference Papers　2014

    Publisher: Optical Society of America (OSA)

    DOI： 10.1364/cleo_qels.2014.ff1d.3 　

    ISSN： 2162-2701

  99. Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelength

    Rui-Bo Jin, Ryosuke Shimizu, Kentaro Wakui, Mikio Fujiwara, Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang, Masahide Sasaki

    2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　.　2014

    ISSN： 2160-9020

  100. High-fidelity frequency down-conversion of visible entangled photon pairs with superconducting single-photon detectors

    Rikizo Ikuta, Hiroshi Kato, Yoshiaki Kusaka, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Zhen Wang, Nobuyuki Imoto

    ELEVENTH INTERNATIONAL CONFERENCE ON QUANTUM COMMUNICATION, MEASUREMENT AND COMPUTATION (QCMC)　1633　252-254　2014

    DOI： 10.1063/1.4903153 　

    ISSN： 0094-243X

  101. Performance of Long-Distance Quantum Key Distribution Over 90-km Optical Links Installed in a Field Environment of Tokyo Metropolitan Area

    Kaoru Shimizu, Toshimori Honjo, Mikio Fujiwara, Toshiyuki Ito, Kiyoshi Tamaki, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Zhen Wang, Masahide Sasaki

    JOURNAL OF LIGHTWAVE TECHNOLOGY　32　(1)　141-151　2014/01

    DOI： 10.1109/JLT.2013.2291391 　

    ISSN： 0733-8724

    eISSN： 1558-2213

  102. Low-filling-factor superconducting single photon detector with high system detection efficiency

    Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang

    OPTICS EXPRESS　21　(22)　27177-27184　2013/11

    DOI： 10.1364/OE.21.027177 　

    ISSN： 1094-4087

  103. Observation of two output light pulses from a partial wavelength converter preserving phase of an input light at a single-photon level

    Rikizo Ikuta, Toshiki Kobayashi, Hiroshi Kato, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masahide Sasaki, Zhen Wang, Masato Koashi, Nobuyuki Imoto

    OPTICS EXPRESS　21　(23)　27865-27872　2013/11

    DOI： 10.1364/OE.21.027865 　

    ISSN： 1094-4087

  104. Cryogenic signal processing technology using superconducting single-flux-quantum logic circuit

    Shigehito Miki, Taro Yamashita, Kazumasa Makise, Kenmei Kajino, Zhen Wang, Hirotaka Terai

    Journal of the National Institute of Information and Communications Technology　60　(1)　49-56　2013/10

    ISSN： 1349-3205

  105. Nonclassical two-photon interference between independent telecommunication light pulses converted by difference-frequency generation

    Rikizo Ikuta, Toshiki Kobayashi, Hiroshi Kato, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Zhen Wang, Nobuyuki Imoto

    PHYSICAL REVIEW A　88　(4)　2013/10

    DOI： 10.1103/PhysRevA.88.042317 　

    ISSN： 1050-2947

    eISSN： 1094-1622

  106. Nonclassical interference between independent intrinsically pure single photons at telecommunication wavelength

    Rui-Bo Jin, Kentaro Wakui, Ryosuke Shimizu, Hugo Benichi, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Zhen Wang, Mikio Fujiwara, Masahide Sasaki

    Physical Review A - Atomic, Molecular, and Optical Physics　87　(6)　2013/06/03

    DOI： 10.1103/PhysRevA.87.063801 　

    ISSN： 1050-2947 1094-1622

  107. Design and Fabrication of All-NbN SFQ Circuits for SSPD Signal Processing

    K. Makise, H. Terai, S. Miki, T. Yamashita, Z. Wang

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY　23　(3)　2013/06

    DOI： 10.1109/TASC.2012.2235504 　

    ISSN： 1051-8223

  108. High performance fiber-coupled NbTiN superconducting nanowire single photon detectors with Gifford-McMahon cryocooler

    Shigehito Miki, Taro Yamashita, Hirotaka Terai, Zhen Wang

    OPTICS EXPRESS　21　(8)　10208-10214　2013/04

    DOI： 10.1364/OE.21.010208 　

    ISSN： 1094-4087

  109. Countermeasure against tailored bright illumination attack for DPS-QKD

    Toshimori Honjo, Mikio Fujiwara, Kaoru Shimizu, Kiyoshi Tamaki, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Zhen Wang, Masahide Sasaki

    OPTICS EXPRESS　21　(3)　2667-2673　2013/02

    DOI： 10.1364/OE.21.002667 　

    ISSN： 1094-4087

  110. Non-classical Interference Between Two Telecom Photons with Wavelength Conversion Peer-reviewed

    Toshiki Kobayashi, Rikizo Ikuta, Hiroshi Kato, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Zhen Wang, Nobuyuki Imoto

    2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS PACIFIC RIM (CLEO-PR)　2013

    DOI： 10.1109/CLEOPR.2013.6600353 　

  111. Characterization of optical absorptance in superconducting nanowire single-photon detectors

    Taro Yamashita, Shigehito Miki, Hirotaka Terai, Zhen Wang

    2013 IEEE 14TH INTERNATIONAL SUPERCONDUCTIVE ELECTRONICS CONFERENCE (ISEC)　.　2013

  112. Performances of NbTiN superconducting nanowire single photon detector

    Shigehito Miki, Taro Yamashita, Hirotaka Terai, Zhen Wang

    2013 IEEE 14TH INTERNATIONAL SUPERCONDUCTIVE ELECTRONICS CONFERENCE (ISEC)　.　2013

  113. Technologies for superconducting nanowire single-photon detector array system

    Shigehito Miki, Taro Yamashita, Hirotaka Terai, Kazumasa Makise, Zhen Wang

    ADVANCED PHOTON COUNTING TECHNIQUES VII　8727　2013

    DOI： 10.1117/12.2016750 　

    ISSN： 0277-786X

    eISSN： 1996-756X

  114. High-fidelity conversion of photonic quantum information to telecommunication wavelength with superconducting single-photon detectors

    Rikizo Ikuta, Hiroshi Kato, Yoshiaki Kusaka, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Zhen Wang, Nobuyuki Imoto

    PHYSICAL REVIEW A　87　(1)　2013/01

    DOI： 10.1103/PhysRevA.87.010301 　

    ISSN： 2469-9926

    eISSN： 2469-9934

  115. Parallel bias and readout techniques toward realization of large-scale SSPD array with SFQ circuit

    Taro Yamashita, Shigehito Miki, Hirotaka Terai, Kazumasa Makise, Zhen Wang

    IEEE Transactions on Applied Superconductivity　23　(3)　2013

    DOI： 10.1109/TASC.2012.2234199 　

    ISSN： 1051-8223

    eISSN： 1558-2515

  116. Localization and interaction effects in ultrathin epitaxial NbN superconducting films

    S. Ezaki, K. Makise, B. Shinozaki, T. Odo, T. Asano, H. Terai, T. Yamashita, S. Miki, Z. Wang

    JOURNAL OF PHYSICS-CONDENSED MATTER　24　(47)　2012/11

    DOI： 10.1088/0953-8984/24/47/475702 　

    ISSN： 0953-8984

  117. Low-jitter single flux quantum signal readout from superconducting single photon detector

    Hirotaka Terai, Taro Yamashita, Shigehito Miki, Kazumasa Makise, Zhen Wang

    OPTICS EXPRESS　20　(18)　20115-20123　2012/08

    DOI： 10.1364/OE.20.020115 　

    ISSN： 1094-4087

  118. Crosstalk-free operation of multielement superconducting nanowire single-photon detector array integrated with single-flux-quantum circuit in a 0.1 W Gifford-McMahon cryocooler

    Taro Yamashita, Shigehito Miki, Hirotaka Terai, Kazumasa Makise, Zhen Wang

    OPTICS LETTERS　37　(14)　2982-2984　2012/07

    DOI： 10.1364/OL.37.002982 　

    ISSN： 0146-9592

  119. High-Speed Quantum Key Distribution System for 1-Mbps Real-Time Key Generation Peer-reviewed

    Akihiro Tanaka, Mikio Fujiwara, Ken-ichiro Yoshino, Seigo Takahashi, Yoshihiro Nambu, Akihisa Tomita, Shigehito Miki, Taro Yamashita, Zhen Wang, Masahide Sasaki, Akio Tajima

    IEEE JOURNAL OF QUANTUM ELECTRONICS　48　(4)　542-550　2012/04

    DOI： 10.1109/JQE.2012.2187327 　

    ISSN： 0018-9197

    eISSN： 1558-1713

  120. Field demonstration of high-speed wavelength-division multiplexing quantum key distribution system and its stabilized operation Peer-reviewed

    Ken-Ichiro Yoshino, Mikio Fujiwara, Akihiro Tanaka, Seigo Takahashi, Yoshihiro Nambu, Akihisa Tomita, Shigehito Miki, Taro Yamashita, Zhen Wang, Masahide Sasaki, Akio Tajima

    Technical Digest - 2012 17th Opto-Electronics and Communications Conference, OECC 2012　737-738　2012

    DOI： 10.1109/OECC.2012.6276605 　

  121. Development of fiber-coupled four-element superconducting nanowire single-photon detectors

    Shigehito Miki, Taro Yamashita, Hirotaka Terai, Kazumasa Makise, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    SUPERCONDUCTIVITY CENTENNIAL CONFERENCE 2011　36　77-81　2012

    DOI： 10.1016/j.phpro.2012.06.216 　

    ISSN： 1875-3892

  122. Fluctuation conductance and the Berezinskii-Kosterlitz-Thouless transition in two dimensional epitaxial NbTiN ultrathin films

    K. Makise, H. Terai, T. Yamashita, S. Miki, Z. Wang, Y. Uzawa, S. Ezaki, T. Odou, B. Shinozaki

    26TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT26), PTS 1-5　400　2012

    DOI： 10.1088/1742-6596/400/2/022064 　

    ISSN： 1742-6588

  123. NOVEL PHOTON DETECTION TECHNOLOGIES FOR QUANTUM COMMUNICATIONS

    M. Sasaki, A. Tanaka, M. Fujiwara, K. Yoshino, S. Takahashi, Y. Nambu, A. Tomita, A. Tajima, S. Miki, T. Yamashita, H. Terai, Z. Wang, K. Tsujino, D. Fukuda, M. Takeoka

    ADVANCED PHOTON COUNTING TECHNIQUES VI　8375　2012

    DOI： 10.1117/12.919917 　

    ISSN： 0277-786X

  124. High-speed wavelength-division multiplexing quantum key distribution system

    Ken-ichiro Yoshino, Mikio Fujiwara, Akihiro Tanaka, Seigo Takahashi, Yoshihiro Nambu, Akihisa Tomita, Shigehito Miki, Taro Yamashita, Zhen Wang, Masahide Sasaki, Akio Tajima

    OPTICS LETTERS　37　(2)　223-225　2012/01

    DOI： 10.1364/OL.37.000223 　

    ISSN： 0146-9592

    eISSN： 1539-4794

  125. Origin of intrinsic dark count in superconducting nanowire single-photon detectors

    T. Yamashita, S. Miki, K. Makise, W. Qiu, H. Terai, M. Fujiwara, M. Sasaki, Z. Wang

    APPLIED PHYSICS LETTERS　99　(16)　2011/10

    DOI： 10.1063/1.3652908 　

    ISSN： 0003-6951

  126. Superconducting single photon detectors integrated with single flux quantum readout circuits in a cryocooler

    Shigehito Miki, Hirotaka Terai, Taro Yamashita, Kazumasa Makise, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    APPLIED PHYSICS LETTERS　99　(11)　2011/09

    DOI： 10.1063/1.3640503 　

    ISSN： 0003-6951

  127. Afterpulse-like phenomenon of superconducting single photon detector in high speed quantum key distribution system

    M. Fujiwara, A. Tanaka, S. Takahashi, K. Yoshino, Y. Nambu, A. Tajima, S. Miki, T. Yamashita, Z. Wang, A. Tomita, M. Sasaki

    OPTICS EXPRESS　19　(20)　19562-19571　2011/09

    DOI： 10.1364/OE.19.019562 　

    ISSN： 1094-4087

  128. Field demonstration of quantum key distribution in the Tokyo QKD Network Peer-reviewed

    M. Fujiwara, H. Ishizuka, S. Miki, T. Yamashita, Z. Wang, A. Tanaka, K. Yoshino, Y. Nambu, S. Takahashi, A. Tajima, A. Tomita, T. Hasegawa, T. Tsurumaru, M. Matsui, T. Honjo, K. Tamaki, Y. Tokura, M. Sasaki

    2011 International Quantum Electronics Conference (IQEC) and Conference on Lasers and Electro-Optics (CLEO) Pacific Rim incorporating the Australasian Conference on Optics, Lasers and Spectroscopy and the Australian Conference on Optical Fibre Technology　2011/08

    Publisher: IEEE

    DOI： 10.1109/iqec-cleo.2011.6193793 　

  129. Performances of Fiber-Coupled Superconducting Nanowire Single-Photon Detectors Measured at Ultralow Temperature

    T. Yamashita, S. Miki, W. Qiu, M. Fujiwara, M. Sasaki, Z. Wang

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY　21　(3)　336-339　2011/06

    DOI： 10.1109/TASC.2010.2091244 　

    ISSN： 1051-8223

  130. Characterization of Coupling Efficiency and Absorption Coefficient for Fiber-Coupled SNSPD With an Optical Cavity

    Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY　21　(3)　332-335　2011/06

    DOI： 10.1109/TASC.2010.2091486 　

    ISSN： 1051-8223

  131. Field test of quantum key distribution in the Tokyo QKD Network

    M. Sasaki, M. Fujiwara, H. Ishizuka, W. Klaus, K. Wakui, M. Takeoka, S. Miki, T. Yamashita, Z. Wang, A. Tanaka, K. Yoshino, Y. Nambu, S. Takahashi, A. Tajima, A. Tomita, T. Domeki, T. Hasegawa, Y. Sakai, H. Kobayashi, T. Asai, K. Shimizu, T. Tokura, T. Tsurumaru, M. Matsui, T. Honjo, K. Tamaki, H. Takesue, Y. Tokura, J. F. Dynes, A. R. Dixon, A. W. Sharpe, Z. L. Yuan, A. J. Shields, S. Uchikoga, M. Legre, S. Robyr, P. Trinkler, L. Monat, J. -B. Page, G. Ribordy, A. Poppe, A. Allacher, O. Maurhart, T. Laenger, M. Peev, A. Zeilinger

    OPTICS EXPRESS　19　(11)　10387-10409　2011/05

    DOI： 10.1364/OE.19.010387 　

    ISSN： 1094-4087

  132. Enhancing Detection Efficiency by Applying an Optical Cavity Structure in a Superconducting Nanowire Single-Photon Detector

    Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    IEICE TRANSACTIONS ON ELECTRONICS　E94C　(3)　260-265　2011/03

    DOI： 10.1587/transele.E94.C.260 　

    ISSN： 0916-8524

    eISSN： 1745-1353

  133. A Scalable Full Quantum Key Distribution System based on Colourless Interferometric Technique and Hardware Key Distillation Peer-reviewed

    A. Tanaka, M. Fujiwara, K. Yoshino, S. Takahashi, Y. Nambu, A. Tomita, S. Miki, T. Yamashita, Z. Wang, M. Sasaki, A. Tajima

    2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)　2011

  134. Development of practical superconducting nanowire single photon detector system with high detection efficiency Peer-reviewed

    Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    2011 International Conference on Space Optical Systems and Applications, ICSOS'11　142-147　2011

    DOI： 10.1109/ICSOS.2011.5783658 　

  135. Photon level crosstalk between parallel fibers installed in urban area

    Mikio Fujiwara, Shigehito Miki, Taro Yamashita, Zhen Wang, Masahide Sasaki

    OPTICS EXPRESS　18　(21)　22199-22207　2010/10

    DOI： 10.1364/OE.18.022199 　

    ISSN： 1094-4087

  136. Demonstration of single-flux-quantum readout operation for superconducting single-photon detectors

    Hirotaka Terai, Shigehito Miki, Taro Yamashita, Kazumasa Makise, Zhen Wang

    APPLIED PHYSICS LETTERS　97　(11)　2010/09

    DOI： 10.1063/1.3484965 　

    ISSN： 0003-6951

  137. Multichannel SNSPD system with high detection efficiency at telecommunication wavelength

    Shigehito Miki, Taro Yamashita, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    OPTICS LETTERS　35　(13)　2133-2135　2010/07

    DOI： 10.1364/OL.35.002133 　

    ISSN： 0146-9592

    eISSN： 1539-4794

  138. Multi-channel superconducting nanowire single photon detector system with high detection efficiency

    Taro Yamashita, Shigehito Miki, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　.　2010

  139. Temperature Dependent Performances of Superconducting Nanowire Single-Photon Detectors in an Ultralow-Temperature Region

    Taro Yamashita, Shigehito Miki, Wei Qiu, Mikio Fujiwara, Masahide Sasaki, Zhen Wang

    APPLIED PHYSICS EXPRESS　3　(10)　2010

    DOI： 10.1143/APEX.3.102502 　

    ISSN： 1882-0778

  140. Superconducting quantum bit with pi-junctions Peer-reviewed

    T. Yamashita, S. Takahashi, S. Maekawa

    World Scientific　84-87　2006/07

    More details Close

    edited by S. Ishioka and K. Fujikawa

  141. Controllable pi junction with magnetic nanostructures

    T Yamashita, S Takahashi, S Maekawa

    PHYSICAL REVIEW B　73　(14)　2006/04

    DOI： 10.1103/PhysRevB.73.144517 　

    ISSN： 1098-0121

  142. Superconducting pi qubit with three Josephson junctions

    T Yamashita, S Takahashi, S Maekawa

    APPLIED PHYSICS LETTERS　88　(13)　2006/03

    DOI： 10.1063/1.2189191 　

    ISSN： 0003-6951

    eISSN： 1077-3118

  143. Quantum interference due to crossed Andreev reflection in a d-wave superconductor with two nano-contacts

    S Takahashi, T Yamashita, S Maekawa

    JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS　67　(1-3)　325-328　2006/01

    DOI： 10.1016/j.jpcs.2005.10.163 　

    ISSN： 0022-3697

  144. Superconducting pi qubit with a ferromagnetic josephson junction

    T Yamashita, K Tanikawa, S Takahashi, S Maekawa

    PHYSICAL REVIEW LETTERS　95　(9)　2005/08

    DOI： 10.1103/PhysRevLett.95.097001 　

    ISSN： 0031-9007

    eISSN： 1079-7114

  145. Andreev reflection in ferromagnet/superconductor/ferromagnet junctions

    T. Yamashita, H. Imamura, S. Takahashi, S. Maekawa

    JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　272　E1523-E1524　2004/05

    DOI： 10.1016/j.jmmm.2003.12.386 　

    ISSN： 0304-8853

  146. Crossed Andreev reflection in structures consisting of a superconductor with ferromagnetic leads

    T Yamashita, S Takahashi, S Maekawa

    PHYSICAL REVIEW B　68　(17)　2003/11

    DOI： 10.1103/PhysRevB.68.174504 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  147. Andreev reflection in ferromagnet/superconductor/ferromagnet structures

    T Yamashita, H Imamura, S Takahashi, S Maekawa

    PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES　18　(1-3)　52-53　2003/05

    DOI： 10.1016/S1386-9477(02)00954-2 　

    ISSN： 1386-9477

  148. Andreev reflection in ferromagnet/superconductor/ferromagnet double junction systems

    T Yamashita, H Imamura, S Takahashi, S Maekawa

    PHYSICAL REVIEW B　67　(9)　2003/03

    DOI： 10.1103/PhysRevB.67.094515 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  149. Spin transport and relaxation in superconductors

    T. Yamashita, S. Takahashi, H. Imamura, S. Maekawa

    Physical Review B - Condensed Matter and Materials Physics　65　(17)　1725091-1725094　2002/05/01

    ISSN： 0163-1829

  150. Spin transport and relaxation in superconductors

    T Yamashita, S Takahashi, H Imamura, S Maekawa

    PHYSICAL REVIEW B　65　(17)　2002/05

    DOI： 10.1103/PhysRevB.65.172509 　

    ISSN： 1098-0121

  151. Spin-relaxation and magnetoresistance in FM/SC/FM tunnel junctions

    S Takahashi, T Yamashita, H Imamura, S Maekawa

    JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　240　(1-3)　100-102　2002/02

    ISSN： 0304-8853

  152. Joule heating generated by spin current through Josephson junctions

    S Takahashi, T Yamashita, T Koyama, S Maekawa, H Imamura

    JOURNAL OF APPLIED PHYSICS　89　(11)　7505-7507　2001/06

    ISSN： 0021-8979

Show all ︎Show first 5

Misc. 39

  1. All-Nitride Superconducting Qubit with Epitaxial Josephson Junctions on Si Substrate Peer-reviewed

    Sunmi Kim, Hirotaka Terai, Taro Yamashita, Kunihiro Inomata

    77　(12)　805-810　2022/12

    Publisher: 日本物理学会

    DOI： 10.11316/butsuri.77.12_805 　

  2. Development of single photon detection technology using superconducting nanowire

    116　(446)　17-21　2017/01/30

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  3. 冷却Rb原子集団と通信波長光子間のエンタングルメント実証

    川上哲生, 小林俊輝, 生田力三, 三木茂人, 三木茂人, 山下太郎, 寺井弘高, 山本俊, 小芦雅斗, 向井哲哉, 井元信之

    日本物理学会講演概要集(CD-ROM)　72　(2)　2017

    ISSN： 2189-079X

  4. 冷却Rb原子集団と通信波長光子間のエンタングルメント実証

    川上哲生, 小林俊輝, 生田力三, 三木茂人, 三木茂人, 山下太郎, 寺井弘高, 山本俊, 小芦雅斗, 向井哲哉, 井元信之

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)　78th　2017

    ISSN： 2758-4704

  5. Fabrication of on-chip two-photon interferometer using waveguide-coupled SSPD

    116　(269)　37-42　2016/10/26

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  6. Fabrication of waveguide-coupled SSPD toward on-chip quantum waveguide circuit

    116　(6)　49-54　2016/04/20

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  7. C-8-7 Fabrication of waveguide-coupled SSPD using SOI substrate

    Waki Kentaro, Yamashita Taro, Inoue Shin-ichiro, Miki Shigehito, Terai Hirotaka, Ikuta Rikizo, Yamamoto Takashi, Imoto Nobuyuki

    Proceedings of the IEICE General Conference　2016　(2)　35-35　2016/03/01

    Publisher: The Institute of Electronics, Information and Communication Engineers

  8. CT-1-4 Physics of Ferromagnet/Superconductor Hybrid Structures and its Application to Computing Devices

    Yamashita Taro

    Proceedings of the IEICE General Conference　2016　(2)　"SS-22"-"SS-25"　2016/03/01

    Publisher: The Institute of Electronics, Information and Communication Engineers

  9. Recent progress in ferromagnet/superconductor hybrid structure and its applications to cryogenic computing

    Taro Yamashita, Hirotaka Terai

    IEEJ Transactions on Fundamentals and Materials　136　(12)　728-733　2016

    Publisher: Institute of Electrical Engineers of Japan

    DOI： 10.1541/ieejfms.136.728 　

    ISSN： 1347-5533 0385-4205

  10. Fabrication and characterization of waveguide-coupled superconducting nanowire single-photon detectors

    WAKI Kentaro, YAMASHITA Taro, INOUE Shin-ichiro, MIKI Shigehito, TERAI Hirotaka, IKUTA Rikizo, YAMAMOTO Takashi, IMOTO Nobuyuki

    Technical report of IEICE. SCE　114　(247)　17-21　2014/10/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    In recent years, the waveguide-coupled type of superconducting nanowire single-photon detectors (SSPDs), which consists of a superconducting nanowire prepared on the optical waveguide, has been studied for monolithically-integrated quantum photonic circuits (MIQPCs) which is composed of various quantum optical components, such as single photon sources and detectors. In the waveguide-coupled SSPD, evanescent photons that escape from the waveguide are absorbed in a superconducting nanowire, and can be detected through an electrical pulse by a temporary transition to the normal state. As first step toward realization of the waveguide-coupled SSPD, we report the fabrication and characterization of an NbTiN-based waveguide-coupled SSPD on the silicon waveguide by using silicon-on-insulator (SOI) substrate.

  11. 9aAZ-3 Observation of two-photon interference by using a frequency-domain beamsplitter

    Kobayashi Toshiki, Yasui Shuto, Ikuta Rikizo, Miki Shigehito, Yamashita Taro, Fujiwara Mikio, Yamamoto Takashi, Koashi Masato, Sasaki Masahide, Wang Zhen, Imoto Nobuyuki

    Meeting abstracts of the Physical Society of Japan　69　(2)　83-83　2014/08/22

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  12. 9aAZ-4 Frequency down-conversion of 637 nm light to the telecommunication band for non-classical light emitted from NV centers in diamond

    Yasui Shuto, Ikuta Rikizo, Kobayashi Toshiki, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Fujiwara Mikio, Yamamoto Takashi, Koashi Masato, Sasaki Masahide, Zhen Wang, Imoto Nobuyuki

    Meeting abstracts of the Physical Society of Japan　69　(2)　83-83　2014/08/22

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  13. 9aAZ-2 Observation of two output light pulses from a partial wavelength converter preserving phase of an input light at a single-photon level

    Ikuta Rikizo, Kobayashi Toshiki, Kato Hiroshi, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Fujiwara Mikio, Yamamoto Takashi, Koashi Masato, Sasaki Masahide, Wang Zhen, Imoto Nobuyuki

    Meeting abstracts of the Physical Society of Japan　69　(2)　82-82　2014/08/22

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  14. Nonclassical interference between independent intrinsically pure single photons at telecommunication wavelength (vol 87, 063801, 2013)

    Rui-Bo Jin, Kentaro Wakui, Ryosuke Shimizu, Hugo Benichi, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Zhen Wang, Mikio Fujiwara, Masahide Sasaki

    PHYSICAL REVIEW A　89　(4)　2014/04

    DOI： 10.1103/PhysRevA.89.049905 　

    ISSN： 1050-2947

    eISSN： 1094-1622

  15. CT-1-8 SFQ readout circuit for superconducting single-photon detector array

    Terai Hirotaka, Miki Shigehito, Yamashita Taro, Makise Kazumasa, Kajino Kemmei, Wang Zhen

    Proceedings of the IEICE General Conference　2014　(2)　"SS-24"-"SS-27"　2014/03/04

    Publisher: The Institute of Electronics, Information and Communication Engineers

  16. CT-1-7 Progress of single photon detection technology using superconducting nanowire

    Miki Shigehito, Yamashita Taro, Wang Zhen, Terai Hirotaka

    Proceedings of the IEICE General Conference　2014　(2)　"SS-20"-"SS-23"　2014/03/04

    Publisher: The Institute of Electronics, Information and Communication Engineers

  17. ダイヤモンド中のNV中心のための637nmから通信波長帯への波長変遷実験

    安井崇人, 生田力三, 小林俊輝, 三木茂人, 山下太郎, 寺井弘高, 藤原幹生, 山本俊, 小芦雅斗, 佐々木雅英, WANG Zhen, 井元信之

    日本物理学会講演概要集　69　(2)　2014

    ISSN： 1342-8349

  18. Development of Superconducting Single Photon Detector System

    MIKI Shigehito, YAMASHITA Taro, TERAI Hirotaka, WANG Zhen

    Technical report of IEICE. SCE　113　(232)　49-54　2013/10/02

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    Superconducting single photon detector array for visible to near infrared wavelength region is expected as promising technology achieving ultra high speed operation, pseudo photon number resolving, spatial resolving, and so on. In order to develop large scale SSPD array system, device fabrication, system development, and signal processing scheme are essential technologies. In this paper, we introduce the current R&D status of SSPD array system in our group. We report on successful fabrication of four pixel SSPD array, and verified their superconductivity and optical characteristics. The successful operation of four pixel SSPD array connected with single flux quantum circuit installed in a GM cryocooler system.

  19. High detection efficiency superconducting nanowire single-photon detector with low filling factor

    YAMASHITA Taro, MIKI Shigehito, TERAI Hirotaka, WANG Zhen

    Technical report of IEICE. SCE　113　(232)　55-60　2013/10/02

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    We present a numerical simulation of the optical absorptance for the superconducting nanowire single-photon detectors (SSPDs) designed with various layouts by using finite-element analysis software. The simulation results reveal that the electric field concentrated in the superconducting nanowire is enhanced by reducing the filling factor, and the degree of the enhancement becomes larger for thicker nanowires. Due to the large enhancement of the electric field in the nanowire with a double-side cavity structure, the high optical absorptance can be achieved even for the low-filling-factor layout by tuning the device design, which leads to the realization of SSPDs with high system detection efficiency and high counting rate.

  20. 26aED-2 Observation of non-classical interference between two telecom photons frequency-down-converted from visible wavelength

    Ikuta Rikizo, Kato Hiroshi, Kusaka Yoshiaki, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Fujiwara Mikio, Yamamoto Takashi, Koashi Masato, Sasaki Masahide, Wang Zhen, Imoto Nobuyuki

    Meeting abstracts of the Physical Society of Japan　68　(1)　183-183　2013/03/26

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  21. Superconducting Single-Flux-Quantum Logic Circuit Toward an Innovation in Information and Communications Technology

    TERAI Hirotaka, YAMASHITA Taro, MIKI Shigehito, MAKISE Kazumasa, WANG Zhen

    48　(2)　77-82　2013/02/25

    Publisher: 低温工学・超電導学会

    ISSN： 0389-2441

  22. Fabrication and characteristics evaluation of superconducting single photon detector on Si substrate

    Higashi Tomohiro, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Yamamoto Takashi, Imoto Nobuyuki, Wang Zhen

    Technical report of IEICE. SCE　112　(408)　1-6　2013/01/24

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    Superconducting single photon detectors (SSPDs) are highly promising devices for single-photon detection at telecommunication wavelengths, and applied in the field of quantum information and communication technology If we achieve high performance SSPD on the silicon (S1) substrate that is the main material for the optical circuit, we can realize integration of various optical elements and SSPD on the S1 substrate This contributes greatly to the development of quantum optics and quantum information and communication technology We performed optimization of the conditions of NbN thin film on the S1 substrate, and fabricated the SSPD device on S1 substrate at optimized condition We also measured superconducting properties and system detection efficiency, which was found to be 6 4 %, 7 8 % at wavelengths of 1550 and 1310 nm, respectively

  23. 24pBE-4 Observation of high-fidelity wavelength conversion of a quantum state with a superconducting single photon detector

    Ikuta Rikizo, Kato Hiroshi, Kusaka Yoshiaki, Miki Shigehito, Yamashita Taro, Terai Hirotaka, Fujiwara Mikio, Yamamoto Takashi, Koashi Masato, Sasaki Masahide, Wang Zhen, Imoto Nobuyuki

    Meeting abstracts of the Physical Society of Japan　67　(1)　193-193　2012/03/05

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  24. Origin of dark count in superconducting nanowire single-photon detectors

    YAMASHITA Taro, MIKI Shigehito, MAKISE Kazumasa, QIU Wei, TERAI Hirotaka, FUJIWARA Mikio, SASAKI Masahide, WANG Zhen

    Technical report of IEICE. SCE　111　(230)　1-6　2011/10/05

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    We investigated a physical mechanism of the dark count in superconducting nanowire single-photon detectors. The direct-current characteristics and bias-current dependencies of the dark count rate in a wide range of temperatures from 0.5 K to 4 K were measured. As a candidate for the origin of the dark count, we examined two possible mechanisms: (i) the current-assisted unbinding of vortex-antivortex pairs induced by the Berezinskii-Kosterlitz-Thouless transition and (ii) the vortex hopping overcoming the edge barrier of the nanowire. Our results indicate that the unbinding of vortex-antivortex pairs is the dominant origin of the dark count.

  25. Demonstration of SFQ readout operation for realizing SSPD array

    TERAI Hirotaka, MIKI Shigehito, YAMASHITA Taro, MAKISE Kazumasa, WANG Zhen

    IEICE technical report　110　(235)　43-48　2010/10/12

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    A readout circuit using superconducting single-flux-quantum (SFQ) circuits has been developed to realize an independently addressable array of superconducting single-photon detectors (SSPDs). We tested the SFQ readout circuits by connecting with SSPDs. The error rates of readout circuits were below 10^<-5> for input signal amplitude of greater than 18.2μA. Detection efficiencies (DEs) for single-photon incidents were measured both with and without the connection of a readout circuit. The observed DEs traced almost the same curves regardless of the connection of the readout circuit, except that the SSPD is likely to latch by connecting the readout circuit.

  26. Ferromagnetic pi-junction and superconducting quantum bit

    T. Yamashita, S. Takahashi, S. Maekawa

    Solid State Physics　40　(10)　763-772　2005/10

    Publisher: Agne Gijutsu Center

  27. 26pYT-12 Theory of superconducting quantum bit with pi junction

    Yamashita T, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　60　(0)　652-652　2005

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  28. 12aPS-27 Crossed Andreev Reflection in a 2-lead Josephson Junction with a Ferromagnetic π-Junction

    Tanikawa K, Yamashita T, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　59　(0)　346-346　2004

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  29. 13pWB-12 Josephson effect in a superconducting ring with a pi-junction

    Yamashita T, Tanikawa K, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　59　(0)　391-391　2004

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  30. 27aPS-52 Spin transport and Andreev reflection in a nanostructure with multi-point contacts

    Takahashi S, Yamashita T, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　59　(0)　447-447　2004

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  31. 27pYG-10 Josephson effect in a hybrid nanostructure with ferromagnetic leads

    Tanikawa K, Yamashita T, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　59　(0)　679-679　2004

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  32. Crossed Andreev reflection in a superconductor with two ferromagnetic leads

    Yamashita T, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　58　(0)　391-391　2003

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  33. Crossed Andreev reflection in a d-wave superconductor with two quantum point contacts

    Takahashi S, Yamashita T, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　58　(0)　581-581　2003

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  34. Crossed Andreev reflection in ferromagnet/superconductor/ferromagnet structures

    Yamashita T, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　58　(0)　462-462　2003

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  35. Andreev reflection in ferromagnet/superconduclor/ferromagnet structures II

    Yamashita T., Imamura H., Takahashi S., Maekawa S.

    Meeting abstracts of the Physical Society of Japan　57　(2)　404-404　2002/08/13

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  36. 25aYL-2 Andreev reflectionin ferromagnet/superconductor/ferromagnet structures

    Yamashita T, Imamura H, Takahashi S, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　57　(0)　393-393　2002

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  37. Spin Transport in Superconductors

    Takahashi S, Yamashita T, Imamura H, Maekawa S, Fert A

    Meeting Abstracts of the Physical Society of Japan　56　(0)　417-417　2001

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  38. Theory of spin current in Josephson junction

    Yamashita T, Takahashi S, Inamura H, Koyama T, Maekawa S

    Meeting Abstracts of the Physical Society of Japan　56　(0)　417-417　2001

    Publisher: The Physical Society of Japan

    ISSN： 1342-8349

  39. Spin-Current in Josephson Junctions

    TAKAHASHI S, YAMASHITA T, IMAMURA H, KOYAMA T, MAEKAWA S

    日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan　24　37-37　2000/09/01

    ISSN： 1340-8100

Show all ︎Show first 5

Presentations 90

  1. Quantum applications of ferromagnet/superconductor hybrid devices Invited

    Taro Yamashita

    The 13th Workshop on Semiconductor/Superconductor Quantum Coherence Effect and Quantum Information　2024/09/25

  2. Novel superconducting flux qubits with improved scalability Invited

    Taro Yamashita

    Quantum, Cryogenic and Superconductive Computing (QUEST2024)　2024/09/09

  3. 超伝導量子コンピュータにおける材料科学 Invited

    山下太郎

    第5回東北大学材料科学フェスタ2024　2024/08/02

  4. 超伝導スピントロニクス技術による超伝導量子ビットの拡張性向上 Invited

    山下太郎

    第93回スピントロニクス専門研究会　2024/06/20

  5. Scalable and Flux-bias-free Superconducting Flux Quantum Bits Invited

    Taro Yamashita

    MRM2023/IUMRS-ICA2023　2023/12/12

  6. 超伝導スピントロニクスによるスケーラブルな超伝導量子回路 Invited

    山下太郎

    第84回応用物理学会秋季学術講演会　2023/09/22

  7. Novel superconducting flux quantum bits toward large-scale quantum circuits Invited

    Taro Yamashita

    15th international workshop on High Temperature Superconductors in High Frequency Fields (HTSHFF2023)　2023/09/12

  8. Flux-bias-free superconducting flux qubits with coplanar waveguide resonator

    Taro Yamashita, Kunihiro Inomata, Duong Pham, Hirotaka Terai

    16th European Conference on Applied Superconductivity (EUCAS2023)　2023/09/04

  9. Niobium nitride based ferromagnetic Josephson junctions toward quantum applications Invited

    Taro Yamashita

    The 11th East Asia Symposium on Superconductor Electronics (EASSE 2023)　2023/03/28

  10. Superconducting flux quantum bits with scalable structures Invited

    Taro Yamashita

    Research Workshop on Superconductivity and Quantum Technology　2023/03/13

  11. 新規量子デバイス創出に向けた超伝導スピントロニクス技術 Invited

    山下太郎

    第28回渦糸物理ワークショップ　2022/12/16

  12. Novel ferromagnet/superconductor hybrid quantum devices Invited

    Taro Yamashita

    2022 Japan–Taiwan Advanced Quantum Technology Research and Development Workshop　2022/11/25

  13. フィードバックループを含む単一磁束量子回路の高周波設計に向けたカウンターフロー方式シフトレジスタのタイミング解析 International-presentation

    長岡一起, 加島亮太, 田中雅光, 山下太郎, 藤巻朗

    2020年電子情報通信学会ソサイエティ大会　2020/09/17

  14. 低消費電力単一磁束量子回路における論理ゲートのタイミングパラメータ解析 International-presentation

    国吉真波, 長岡一起, 田中雅光, 山下太郎, 藤巻朗

    2020年電子情報通信学会ソサイエティ大会　2020/09/17

  15. 単一磁束量子回路に基づく並列処理データパスの 64GHz動作実証 International-presentation

    加島亮太, 長岡一起, 田中雅光, 山下太郎, 藤巻朗

    2020年電子情報通信学会ソサイエティ大会　2020/09/17

  16. SFQアニーラにおける隣接するスピン間の相互作用の影響 International-presentation

    東正志, 長谷川大輝, 竹下雄登, 李峰, 田中雅光, 山下太郎, 藤巻朗

    第81回応用物理学会秋季学術講演会　2020/09/08

  17. 半磁束量子回路の実現に向けた基本素子の作製 International-presentation

    長谷川大輝, 加藤健人, 東正志, 竹下雄登, 李峰, 田中雅光, 山下太郎, 藤巻朗

    第81回応用物理学会秋季学術講演会　2020/09/08

  18. π位相シフタに向けたコバルト障壁層をもつ強磁性ジョセフソン接合の作製と評価 International-presentation

    中村颯, 杉本理駆, PhamDuong, 田中雅光, 山下太郎, 藤巻朗

    第81回応用物理学会秋季学術講演会　2020/09/08

  19. SFQパルス駆動型超伝導メモリ実現に向けたメモリセルの静特性評価 International-presentation

    竹下雄登, 李峰, 長谷川大輝, 加藤健人, 田中雅光, 山下太郎, 藤巻朗

    第81回応用物理学会秋季学術講演会　2020/09/08

  20. 広帯域配線を備えた超伝導デジタル回路用冷凍機システムの特性評価 International-presentation

    村瀬健, 藤巻朗, 山下太郎, 田中雅光, 佐野京佑

    第81回応用物理学会秋季学術講演会　2020/09/08

  21. 超伝導デバイスを用いた量子計算回路 International-presentation

    山下太郎

    令和2年電気学会基礎・材料・共通部門大会　2020/09/03

  22. 強磁性π状態による位相制御 International-presentation

    山下太郎

    電子・光コヒーレント変換研究会　2020/03/19

  23. 低電圧駆動単一磁束量子回路における論理ゲートのタイミングパラメータの解析 International-presentation

    国吉 真波, 村瀬 健, 長岡 一起, 佐野 京佑, 田中 雅光, 山下 太郎, 藤巻 朗

    2020年電子情報通信学会総合大会　2020/03/17

  24. 単一磁束量子回路に基づく低電圧駆動ゲートレベルパイプライン算術論理演算器の設計と評価 International-presentation

    長岡一起, 田中雅光, 佐野京佑, 山下太郎, 井上弘士, 藤巻朗

    電子情報通信学会2020年総合大会　2020/03/17

  25. 単一磁束量子回路に基づく50 GHz並列処理データパスの設計 International-presentation

    加島亮太, 長岡一起, 田中雅光, 佐野京佑, 山下太郎, 藤巻朗

    電子情報通信学会2020年総合大会　2020/03/17

  26. 低電圧駆動単一磁束量子回路における論理ゲートのタイミングパラメータの解析 International-presentation

    国吉真波, 村瀬健, 長岡一起, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    電子情報通信学会2020年総合大会　2020/03/17

  27. Phase-shift flux qubit with a ferromagnetic π junction

    T. Yamashita, Kun Zuo, Y.Urade, W. Qiu, H.Terai, A.Fujimaki, Y.Nkamura

    APS March Meeting 2020　2020/03/02

  28. Development and evaluation of superconducting n anowire single photon detect o rs with dielectric multilayers

    F. China, S. Miki, M. Yabuno, T. Yamashita, H. Terai

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  29. Investigation of timing design by using low-power SFQ shift registers

    M. Kuniyoshi, K. Murase, I. Nagaoka, K. Sano, M. Tanaka, T. Yamashita, A. FUJIMAKI

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  30. Fabrication of magnetic Josephson junctions on Nb 4 layer structure for large scale half flux quantum circuits

    D. Hasegawa, Y. Takeshita, F. Li, K. Sano, M. Tanaka, T. Yamashita, A. Fujimaki

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  31. Demonstration of SQUIDs with a period of half flux quantum in modulation patterns for half flux quantum circuits

    Y. Takeshita, F. Li, D. Hasegawa, K. Sano, M. Tanaka, T. Yamashita, A. Fujimaki

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  32. Development of gate-level-pipelined SFQ circuits toward ultra-high-speed cryogenic computing Invited

    M. Tanaka, I. Nagaoka, K. Ishida, K. Sano, T. Yamashita, T. Ono, K. Inoue, A. Fujimaki

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  33. Simulation and comparison of the energy efficiency of half flux quantum circuits

    F. Li, Y. Takeshita, D. Hasegawa, K. Sano, M. Tanaka, T. Yamashita, A. Fujimaki

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  34. Design of datapath for 8 bit parallel SFQ microprocessors with gate level pipelines

    R. Kashima, I. Nagaoka, M. Tanaka, K. Sano, T. Yamashita, A. Fujimaki

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  35. High-throughput gate-level-pipelined SFQ multipliers

    I. Nagaoka, M. Tanaka, K. Sano, T. Yamashita, K. Inoue, A. Fujimaki

    13th Superconducting SFQ VLSI Workshop (SSV 2020)　2020/01/16

  36. Energy consumption of half flux quantum circuits using π-shifted josephson junctions

    F. Li, Y. Takeshita, D. Hasegawa, K. Sano, M. Tanaka, T. Yamashita, A. Fujimaki

    32st Int. Symp. Supercond. (ISS 2020)　2019/12/03

  37. π-shifted SQUID based circuits and applications for classical computing and beyond

    M. Tanaka, Y. Takeshita, D. Hasegawa, F. Li, K. Sano, T. Yamashita, A. Fujimaki

    1st Workshop on Quantum and Classical Cryogenic Devices, Circuits, and Systems (QCCC 2019)　2019/11/12

  38. 単一磁束量子回路と超伝導ナノデバイスの集積化プロセスの検討 International-presentation

    近藤真生, 佐野京佑, 田中雅光, 山下太郎, 井上真澄, 藤巻朗

    第80回応用物理学会秋季学術講演　2019/09/18

  39. 単一磁束量子回路と超伝導ナノデバイスの集積化プロセスの検討 International-presentation

    長谷川大輝, 竹下雄登, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    第80回応用物理学会秋季学術講演　2019/09/18

  40. Nb４層超伝導集積回路上での磁性ジョセフソン接合の作製 International-presentation

    竹下雄登, 長谷川大輝, 神谷智大, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    第80回応用物理学会秋季学術講演　2019/09/18

  41. 磁場変調パターンが半磁束量子周期となるSQUIDの作製 International-presentation

    竹下雄登, 長谷川大輝, 神谷智大, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    第80回応用物理学会秋季学術講演　2019/09/18

  42. 単一磁束量子回路に基づく低電圧駆動ゲートレベルパイプライン算術論理演算器の設計と評価 International-presentation

    田中雅光, 長岡一起, 石田浩貴, 佐野京佑, 山下太郎, 小野貴継, 井上弘士, 藤巻朗

    電子情報通信学会2019年ソサイエティ大会　2019/09/10

  43. Numerical and experimental analysis on π-shifted SQUIDs for logic circuits and memories Invited

    A. Fujimaki, Y. Takeshita, D. Hasegawa, F. Li, K. Sano, M. Tanaka, T. Yamashita

    14th European Conference on Applied Superconductivity (EUCAS 2019)　2019/09/01

  44. Monolithic ICs of Josephson junctions and nTrons for large-capacity memories Invited

    K. Sano, N. Kondo, M. Tanaka, T. Yamashita, M. Inoue, A. Fujimaki

    14th European Conference on Applied Superconductivity (EUCAS 2019)　2019/09/01

  45. ランダムアクセスメモリにおける超伝導ナノ構造ラインドライバの検討 International-presentation

    佐野京佑, 近藤真生, 田中雅光, 山下太郎, 井上真澄, 藤巻朗

    超伝導エレクトロニクス研究会　2019/08/09

  46. Magnetic Josephson junctions on Nb four-layer structure for half flux quantum circuits

    D. Hasegawa, Y. Takeshita, K. Sano, M. Tanaka, T. Yamashita, A. Fujimaki

    17th Int. Supercond. Electron. Conf. (ISEC 2019)　2019/07/28

  47. Impulse-driven high-speed matrix memory based on π-shifted Josephson junctions

    A. Fujimaki, Y. Takeshita, T. Kamiya, D. Hasegawa, K. Sano, M. Tanaka, T. Yamashita

    17th Int. Supercond. Electron. Conf. (ISEC 2019)　2019/07/28

  48. Demonstration of an Energy-Efficient, Gate-Level-Pipelined 100 TOPS/W Arithmetic Logic Unit Based on Low-Voltage Rapid Single-Flux-Quantum Logic

    I. Nagaoka, M. Tanaka, K. Sano, T. Yamashita, K. Inoue, A. Fujimaki

    17th Int. Supercond. Electron. Conf. (ISEC 2019)　2019/07/28

  49. Numerical analysis of low-power logic family based on half flux quantum using π-shifted Josephson junctions

    M. Tanaka, T. Kamiya, Y. Takeshita, D. Hasegawa, K. Sano, T. Yamashita, A. Fujimaki

    17th Int. Supercond. Electron. Conf. (ISEC 2019)　2019/07/28

  50. 単一磁束量子回路に基づくゲートレベル・パイプライン算術論理演算器の高エネルギー効率化と0.3mW, 30GHz動作実証 International-presentation

    田中雅光, 長岡一起, 石田浩貴, 佐野京佑, 山下太郎, 小野貴継, 井上弘士, 藤巻朗

    2019年並列／分散／協調処理に関する『北見』サマー・ワークショップ（SWoPP2019）　2019/07/24

  51. ビット並列演算ゲートレベルパイプラインを用いた単一磁束量子乗算器における高周波動作の評価 International-presentation

    長岡一起, 田中雅光, 佐野京佑, 山下太郎, 井上弘士, 藤巻朗

    電子情報通信学会2019年総合大会　2019/03/19

  52. SFQパルス駆動マトリクスメモリの実現に向けた動作解析 International-presentation

    竹下雄登, 神谷智大, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    第65回応用物理学会春季学術講演会　2019/03/17

  53. 1-Gb Josephson-CMOSハイブリッドメモリに向けた超伝導ナノ構造ラインドライバの検討 International-presentation

    佐野京佑, 丸山晃平, 田中雅光, 山下太郎, 井上真澄, 藤巻朗

    第65回応用物理学会春季学術講演会　2019/03/17

  54. 強磁性ジョセフソン接合と量子回路応用 International-presentation

    山下太郎

    日本物理学会第74回年次大会　2019/03/14

  55. 単一磁束量子ゲートレベルパイプラインマイクロプロセッサに向けた30GHzデータパスの開発 International-presentation

    長岡一起, 畑中湧貴, 松井裕一, 石田浩貴, 田中雅光, 佐野京佑, 山下太郎, 小野貴継, 井上弘士, 藤巻朗

    超伝導エレクトロニクス研究会　2019/01/23

  56. 0-π SQUID based matrix memory driven by SFQ pulses

    Y. Takeshita, T. Kamiya, K. Sano, M. Tanaka, T. Yamashita, A. Fujimaki

    12th Superconducting SFQ VLSI Workshop (SSV 2019)　2019/01/16

  57. Design and Evaluation of superconducting nano-structured line drivers for Josephson-CMOS hybrid memory

    K. Sano, K. Maruyama, M. Tanaka, T. Yamashita, M. Inoue, A. Fujimaki

    12th Superconducting SFQ VLSI Workshop (SSV 2019)　2019/01/16

  58. Fabrication and characterization of ferromagnetic Josephson junctions for π-shift superconducting flux quantum bit

    H. Kato, T. Kamiya, S. Kim, W. Qiu, A. Kawakami, H. Terai, K. Semba, T. Yamashita, A. Fujimaki

    12th Superconducting SFQ VLSI Workshop (SSV 2019)　2019/01/16

  59. Adiabatic quantum-flux-parametron logic as a readout interface for superconducting nanowire single photon detectors

    A. Fujimaki, T. Kamiya, Y. Takeshita, H. Kato, I. Nagaoka, K. Sano, M. Tanaka, T. Yamashita

    12th Superconducting SFQ VLSI Workshop (SSV 2019)　2019/01/16

  60. Development of superconducting quantum circuit with π-junction qubit

    S. Kim, T. Yamashita, F. Yoshihara, T. Fuse, W. Qiu, Z. Ao, H. Terai, K. Semba

    12th Superconducting SFQ VLSI Workshop (SSV 2019)　2019/01/16

  61. Road to superconductor-based world-fastest computer

    A. Fujimaki, T. Kamiya, Y. Takeshita, H. Kato, I. Nagaoka, K. Sano, M. Tanaka, T. Yamashita

    12th Superconducting SFQ VLSI Workshop (SSV 2019)　2019/01/16

  62. 0.1W, 4K GM冷凍機を用いた単一磁束量子デジタル回路システム International-presentation

    田中雅光, 近藤真生, 佐野京佑, 山下太郎, 藤巻朗

    第97回低温工学・超電導学会　2018/11/19

  63. DC-offset-free quantum flux parametron using ferromagnet phase shift elements

    M. Tanaka, H. Ito, S. Taniguchi, H. Iwashita, K. Sano, T. Yamashita, A. Fujimaki

    Applied Superconductivity Conference 2018(ASC2018)　2018/10/28

  64. Low-power half single flux quantum circuits based on π-shifted Josephson junctions

    Tomohiro Kamiya, Yuto Takeshita, Kyosuke Sano, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  65. Fabrication of NbTiN Josephson junctions with thermally oxidized Hf tunnel barriers

    Hiroyuki Akaike, Kentaro Munemoto, Yoshito Sakakibara, Akira Fujimaki

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  66. NbN-based ferromagnetic Josephson junctions for π-shift superconducting flux qubits

    Taro Yamashita, Akira Kawakami, Hirotaka Terai, Akira Fujimaki

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  67. Power-controllable superconducting AC/DC converters for DC-driven energy-efficient single-flux-quantum circuits

    Akira Fujimaki, Soya Taniguchi, Haruki Kato, Hayato Iwashita, Taro Yamashita, Masamitsu Tanaka

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  68. Short turn-on-delay superconducting nanostructure transistors

    Kyosuke Sano, Masato Suzuki, Kohei Maruyama, Naoki Kondo, Masamitsu Tanaka, Taro Yamashita, Masumi Inoue, Akira Fujimaki

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  69. A single-flux-quantum based event-driven encoder for a large-pixel superconducting nanowire single-photon detector array

    Shigeyuki Miyajima, Masahiro Yabuno, Shigehito Miki, Taro Yamashita, Hirotaka Terai

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  70. Demonstration of a superconducting nanowire single-photon detector using adiabatic quantum-flux-parametron logic in a 0.1 W Gifford-McMahon cryocooler

    N. Takeuchi, T. Yamashita, S. Miyajima, S. Miki, N. Yoshikawa, H. Terai

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  71. Timing jitter characterization of a superconducting photon coincidence counter

    Shigehito Miki, Shigeyuki Miyajima, Masahiro Yabuno, Taro Yamashita, Takashi Yamamoto, Nobuyuki Imoto, Rikizo Ikuta, Robert Kirkwood, Robert Hadfield, Hirotaka Terai

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  72. Study on the nanocryotron properties by the numerical calculation

    Masumi Inoue, Yuki Goto, Kyosuke Sano, Taro Yamashita, Masamitsu Tanaka, Akira Fujimaki

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  73. 30-GHz operation of datapath for bit-parallel, gate-level-pipelined rapid single-flux-quantum microprocessors

    Masamitsu Tanaka, Yuki Hatanaka, Yuichi Matsui, Ikki Nagaoka, Koki Ishida, Kyosuke Sano, Taro Yamashita, Takatsugu Ono, Koji Inoue, Akira Fujimaki

    2018 Applied Superconductivity Conference (ASC 2018)　2018/10/28

  74. 超伝導量子ビットに向けたTiNバッファ層付きSi基板上強磁性ジョセフソン接合の作製 International-presentation

    加藤悠輝, 神谷智大, 金鮮美, 丘偉, 川上彰, 寺井弘高, 仙場浩一, 山下太郎, 藤巻朗

    第79回応用物理学会秋季学術講演会　2018/09/18

  75. 半磁束量子を情報担体とした低エネルギー信号伝搬 International-presentation

    田中雅光

    第79回応用物理学会秋季学術講演会　2018/09/18

  76. 強磁性πジョセフソン接合を用いたトグルフリップフロップの作製 International-presentation

    神谷智大, 竹下雄登, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    第79回応用物理学会秋季学術講演会　2018/09/18

  77. 単一磁束量子回路とナノクライオトロンのモノリシック化の検討 International-presentation

    丸山晃平, 佐野京佑, 田中雅光, 山下太郎, 井上真澄, 藤巻朗

    第79回応用物理学会秋季学術講演会　2018/09/18

  78. 単一磁束量子回路における磁場を用いた可変遅延線の提案 International-presentation

    松井裕一, 田中雅光, 佐野京佑, 山下太郎, 藤巻朗

    電子情報通信学会2018年ソサイエティ大会　2018/09/11

  79. 単一磁束量子回路に基づくビット並列演算ゲートレベルパイプライン乗算器の試作と評価 International-presentation

    長岡一起, 佐野京佑, 田中雅光, 山下太郎, 藤巻朗

    電子情報通信学会2018年ソサイエティ大会　2018/09/11

  80. Development of π-shift superconducting flux qubits

    Taro Yamashita

    13th International Workshop on Low Temperature Electronics (WOLTE 13)　2018/09/10

  81. Superconducting nano-structured line drivers in Josephson-CMOS hybrid memory

    Kyosuke Sano, Kohei Maruyama, Naoki Kondo, Masamitsu Tanaka, Taro Yamashita, Masumi Inoue, Akira Fujimaki

    13th International Workshop on Low Temperature Electronics (WOLTE 13)　2018/09/10

  82. 0-π SQUIDによるSFQパルス駆動マトリクスメモリの提案 International-presentation

    山下 太郎, 川上 彰, 寺井 弘高

    超伝導エレクトロニクス研究会　2018/08/09

  83. Progress in DC-powered single-flux-quantum integrated circuits

    Akira Fujimaki, Kyosuke Sano, Taro Yamashita, Masamitsu Tanaka

    4th International Workshop on Superconducting Sensors and Detectors (IWSSD 2018)　2018/07/24

  84. 表面障壁の制御による超伝導三端子素子の可能性 International-presentation

    佐野京佑, 鈴木雅斗, 丸山晃平, 近藤真生, 田中雅光, 山下太郎, 井上真澄, 藤巻朗

    第96回低温工学・超電導学会　2018/05/28

  85. 位相シフト型磁束量子ビットに向けた強磁性ジョセフソン接合の開発 International-presentation

    山下 太郎, 川上 彰, 寺井 弘高

    第65回応用物理学会 春季学術講演会　2018/03/17

  86. Niobium-nitride Based Ferromagnetic Josephson Junctions for Superconducting Qubit Application Invited

    30th International Symposium on Superconductivity　2017/12/13

  87. 窒化ニオブを用いた強磁性ジョセフソン接合におけるπ状態 International-presentation

    山下 太郎, 川上 彰, 寺井 弘高

    日本物理学会 秋季大会　2017/09/12

  88. 量子計算応用に向けた強磁性ジョセフソン接合の作製 International-presentation

    山下 太郎, 川上 彰, 寺井 弘高

    第78回応用物理学会秋季学術講演会　2017/09/05

  89. Development of ferromagnetic Josephson junction based on niobium nitride

    Adiabatic Quantum Computing Conference 2017　2017/06/26

  90. Ferromagnetic Josephson junctions with niobium nitride

    APS March Meeting 2017 APS March Meeting　2017/03/13

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Industrial Property Rights 11

  1. 信号処理回路

    三木茂人, 寺井弘高, 山下太郎, 宮嶋茂之

    Property Type: Patent

  2. 蛍光相関分光装置

    山下太郎, 三木茂人, 原口徳子, 寺井弘高

    Property Type: Patent

  3. 超伝導単一光子検出器及び超伝導単一光子検出器の光学設計方法

    山下太郎, 三木茂人, 寺井弘高

    Property Type: Patent

  4. 超伝導単一光子検出器および受光配線の構造決定方法

    山下太郎, 三木茂人, 寺井弘高, 王鎮

    Property Type: Patent

  5. 超伝導単一光子検出システムおよび超伝導単一光子検出方法

    三木茂人, 寺井弘高, 山下太郎, 牧瀬圭正, 王鎮

    Property Type: Patent

  6. 超伝導単一光子検出システムおよび超伝導単一光子検出方法

    三木茂人, 寺井弘高, 山下太郎, 王鎮

    Property Type: Patent

  7. 超伝導単一光子検出器の実装方法

    三木茂人, 山下太郎, 藤原幹夫, 佐々木雅英, 王鎮

    Property Type: Patent

  8. 超伝導量子回路用素子及び超伝導量子計算機

    山下太郎, 内田徳之新

    Property Type: Patent

  9. 光検出装置およびレーザー顕微鏡システム

    三木茂人, 寺井弘高, 山下太郎, 原口徳子

    Property Type: Patent

  10. 超伝導単一光子検出器

    三木茂人, 寺井弘高, 山下太郎

    Property Type: Patent

  11. ジョセフソン量子計算素子及びそれを用いた集積回路

    前川禎通, 山下太郎, 高橋三郎

    Property Type: Patent

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Research Projects 10

  1. Superconducting single-photon detectors for far-infrared wavelength range

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Pioneering)

    Institution: Tohoku University

    2023/06 - 2026/03

  2. 30K以上の温度域で動作する鉄系超伝導体ベース単一光子検出器の開発

    畑野 敬史, 生田 博志, 山下 太郎

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(B)

    Institution: 名古屋大学

    2023/04 - 2026/03

  3. Large-scale superconducting spintronics quantum computing circuits toward the realization of quantum supremacy

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (S)

    Institution: Nagoya University

    2019/06/26 - 2024/03/31

  4. Research on ultra-low power sub-terahertz superconducting quantum digital systems based on pulse-driven circuits

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Specially Promoted Research

    Institution: Nagoya University

    2018/04/23 - 2023/03/31

  5. Spin-induced weak-link device and physics

    Yamashita Taro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Nagoya University

    2018/06/29 - 2021/03/31

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    We studied spin-induced weak-link devices which consist of the superconductor/ferromagnet bilayer. In the measurement of the temperature dependence of the resistance, we observed two-step superconducting transition indicating clearly the local suppression of the superconductivity of the superconducting wire. We investigated the effect of the ferromagnet region on the superconducting critical current and found that the variation of the critical current between the samples increased with increasing the ferromagnet area. From the present study, we obtained the new insight on physical mechanisms in the ferromagnet/superconductor bilayer structures.

  6. Study on programmable adiabatic superconductor circuits using magnetic Josephson junctions

    Takeuchi Naoki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Yokohama National University

    2018/04/01 - 2021/03/31

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    This study aims to achieve programmable superconductor circuits by introducing π junctions to adiabatic quantum-flux-parametron (AQFP); a π junction is a magnetic Josephson junction, and AQFP is low-power superconductor logic. We have established fabrication technology for introducing π junctions to AQFP circuits, established a simulation method for AQFP circuits with π junctions, developed programmable AQFP circuits that utilize π junction-based memories, and demonstrated the programmable AQFP circuits at low temperature. Consequently, we have succeeded in achieving programmable superconductor circuit technology.

  7. 量子超越性を導く超伝導スピントロニクス量子計算回路の創出

    山下 太郎, 田中 雅光, 猪股 邦宏, 宮嶋 茂之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(A)

    Institution: 名古屋大学

    2019/04/01 - 2020/03/31

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    本年度はまず、本研究のコア技術となる強磁性ジョセフソン接合（π接合）を導入した量子ビットの研究開発を進めた。窒化物ベースのπ接合を位相シフタとして組み込んだ共振器結合型の量子ビットの設計及び素子作製まで完了し、現在原理実証及びコヒーレンス時間等の特性評価を進めている。現在のπ接合では磁性層にCuNiを用いているが、より均一性に優れたPdNiを磁性層材料として用いたπ接合の開発も並行して進めた。また、量子回路を低温下で制御するための単一磁束量子回路または半磁束量子回路といった超伝導古典回路に関して、要求される消費電力やそのために必要な物理パラメータを抽出した上で、制御用回路の具体的な回路構成に関して検討を行いシミュレーションベースで回路設計を進めた。今後は特に、量子制御に要求される小さなタイミングジッタ等の仕様を満たしつつ低消費電力性を実現可能な構成を探索していく。さらに、モノリシック化を見据えた量子回路作製プロセスや材料選択に関しても議論を進め、窒化ニオブベースのジョセフソン接合を用いた回路における臨界電流密度やインダクタンス等の回路パラメータ抽出を進めた。今後は得られた回路パラメータをシミュレーションにフィードバックし、実際の回路作製を行う予定である。また、モノリシック化に適した量子・古典ハイブリッド回路の素子構造の検討を開始したほか、将来的により効率的な量子回路及び半磁束量子回路の評価を可能とするため、低雑音アンプやサーキュレータ等の低温コンポーネントを購入し特性評価系の構築を進めた。

  8. 超伝導位相制御素子によるスケーラブル量子技術

    山下 太郎

    Offer Organization: 科学技術振興機構

    System: 戦略的な研究開発の推進 戦略的創造研究推進事業 さきがけ

    Institution: 国立研究開発法人情報通信研究機構

    2016 - 2019

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    本研究は、超伝導量子回路の大規模化における主要な技術課題に対して、超伝導スピントロニクスによる新しい位相制御手法を用いて解決し、スケーラブルな量子技術を実現することを目指します。スピンジョセフソン接合を導入した低デコヒーレンスな超伝導量子ビットと極低消費電力な超伝導信号処理回路を組み合わせることにより、真にスケーラブルかつインテリジェントな超伝導量子計算システムの実現に向けた基盤技術を創出します。

  9. Development of single-photon imaging technology based on large-scale SSPD array

    TERAI HIROTAKA

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: National Institute of Information and Communications Technology

    2014/04/01 - 2018/03/31

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    We developed a fundamental technology for large-scale array of superconducting nanowire single-photon detector (SSPD) with the aim of realizing image sensor with the ultimate sensitivity capable of photon counting in the visible to infrared wavelength range. We designed and tested an encoder circuit based on a single flux quantum (SFQ) circuit that can output a digital code representing address information of pixels that detected photons. We successfully demonstrated the operation of a 64-pixel SSPD array with a signal processing circuit. We also examined a new readout scheme that enables us to reduce the number of wiring to extract the signal from the SSPD array and the introduction of an adiabatic flux quantum parametron (AQFP) circuit that can operate even lower power consumption than the SFQ circuit.

  10. ナノ構造におけるスピンに依存した伝導の理論的研究

    山下 太郎

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 東北大学

    2004 - 2005

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    本年度はまず、強磁性ジョセフソン接合を利用した新奇な量子計算素子(量子ビット)の提案を行った。強磁性ジョセフソン接合では、系に形成されるアンドレーエフ束縛状態がスピン分裂するため、ジョセフソン電流の位相依存性が通常のジョセフソン接合での依存性からπだけずれる。これをπ接合と呼ぶが、我々はπ接合と通常のジョセフソン接合(0接合)を含んだ超伝導リングを考え、この系におけるポテンシャルがπ接合と0接合の競合により、位相空間において縮退した2つの最小値をもつことを示した。そしてこの2つの状態間の量子的なトンネル効果により結合・反結合状態が形成され、これらの状態が量子計算のためのビットとして用いられる。これらの状態はマイクロ波を用いて制御され、超伝導量子干渉素子(SQUID)により状態を検出できる。また多量子ビット間の磁気的な相互作用を利用して、万能量子ゲートの構築も可能である。従来の超伝導量子ビットには、定常的な外部磁場が必要であるという問題点があったが、本提案ではπ接合を用いることでビットの形成に外部磁場を必要としないという大きな利点がある。外部磁場を必要としないため、より小さな量子ビットをつくることができ、周囲の環境との結合によるデコヒーレンスの効果が抑制されることが期待される。 次に我々は、0状態とπ状態を電流により制御可能な、新しいジョセフソン素子の提案を行った。従来の強磁性ジョセフソン接合では、温度または強磁性体の膜厚によってのみ0-π状態が制御されていた。しかし量子ビット等のデバイスへの応用には、電気的に0-π状態を制御できることが望ましい。そこで本提案では、強磁性体から注入されるスピン流によって常伝導体中に生じるスピン蓄積を用いることにより、超伝導/常伝導/超伝導接合における0-π状態の電気的な制御が可能であることを示した。

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Teaching Experience 8

  1. 応用物理学実験　東北大学

  2. 物性物理原論C　東北大学

  3. 低温・超伝導物理学　東北大学

  4. 電磁気学I　東北大学

  5. 電磁理論　名古屋大学

  6. 微分積分学II　名古屋大学

  7. 物理学実験II　名古屋大学

  8. 量子集積デバイス工学特論　名古屋大学

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