研究成果(論文・学会発表)

2024年度

・Sunmi Kim, Leonid V. Abdurakhimov, Duong Pham, Wei Qiu, Hirotaka Terai, Sahel Ashhab, Shiro Saito, Taro Yamashita, Kouichi Semba,
“Superconducting flux qubit with ferromagnetic Josephson π junction operating at zero magnetic field”,
Communications Materials 5, Article number: 216 (2024).


・Tokunoshin Uchida, Hiroki Kutsuma and Taro Yamashita,
“Self-Shunted Superconducting Flux Qubit”,
IEEE Transactions on Applied Superconductivity, vol. 34, no. 7, 1-8 (2024).


・Naoki Takeuchi, Taiki Yamae, Taro Yamashita, Tsuyoshi Yamamoto, and Nobuyuki Yoshikawa,
“Microwave-multiplexed qubit controller using adiabatic superconductor logic”,
npj Quantum Information, 10, Article number: 53 (2024).


・Duong Pham, Feng Li, Kenjiro Oba, Yuto Takeshita, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki,
“NbN-based tunnel-type π-junctions for low-power half-flux-quantum circuits”,
Superconductor Science and Technology, vol. 37, 055004 (2024).


・Naoki Takeuchi, Mikiya Naruse, Shigeyuki Miyajima, Duong Pham, Hirotaka Terai, Masamitsu Tanaka, and Taro Yamashita,
“NbN-based half-flux-quantum element for integration with superconducting qubits”,
Applied Physics Letters, 124, 152601 (2024).


・Kohki Watanabe, Yoshinao Mizugaki, Satoshi Moriya, Hideaki Yamamoto, Taro Yamashita, and Shigeo Sato,
“Numerical Study on Physical Reservoir Computing With Josephson Junctions”,
IEEE Transactions on Applied Superconductivity, vol. 34, Issue 3 (2024).


・Ikki Nagaoka, Tomoki Nakano, Ryota Kashima, Masamitsu Tanaka, Taro Yamashita, and Akira Fujimaki,
“Investigation of timing margin in single-flux-quantum 4 bit adders for increasing clock frequency of gate-level-pipelined circuits”,
Applied Physics Express, vol. 17, 054501 (2024).

2023年度

・竹内 尚輝, 更田 裕司, 山下 太郎, 山本 剛
「超伝導量子ビット用制御回路 ―現状と課題―」
低温工学 59 巻 2 号 pp. 71-79 (2024).


・Feng Li, Duong Pham, Yuto Takeshita, Masayuki Higashi, Taro Yamashita, Masamitsu Tanaka, and Akira Fujimaki,
“Energy efficient half-flux-quantum circuit aiming at milli-kelvin stage operation”,
Superconductor Science and Technology, 36(10), 105006 (2023).


・R. Kashima, I. Nagaoka, T. Nakano, M. Tanaka, T. Yamashita, A. Fujimaki,
“Lowering Latency in a High-Speed Gate-Level-Pipelined Single Flux Quantum Datapath Using an Interleaved Register File”,
IEEE Transactions on Applied Superconductivity, vol. 33, no. 5, pp. 1-6, Aug. 2023, Art no. 1303306.


・Shigeyuki Miyajima, Taro Yamashita, Masamitsu Tanaka, Naoki Takeuchi, Kunihiro Inomata, Hirotaka Terai,
“Fabrication Process for Monolithic Integration of a Nitride Superconductor-Based Superconducting Qubit with a Single Flux Quantum Control Circuit”,
IEEE Transactions on Applied Superconductivity, vol. 33, no. 5, pp. 1-4, Aug. 2023, Art no. 1100204.


・Masayuki Higashi, Yuto Takeshita, Kento Kato, Hinata Fujisawa, Feng Li, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki,
“Analysis of the Effect of 0-π SQUIDs for Enhancing Mutual Coupling”,
IEEE Transactions on Applied Superconductivity, vol. 33, no. 5, pp. 1-5, Aug. 2023, Art no. 1600805.


・Ikki Nagaoka, Ryota Kashima, Masamitsu Tanaka, Satoshi Kawakami, Teruo Tanimoto, Taro Yamashita, Koji Inoue, Akira Fujimaki,
“50-GFLOPS Floating-Point Adder and Multiplier Using Gate-Level-Pipelined Single-Flux-Quantum Logic With Frequency-Increased Clock Distribution”,
IEEE Transactions on Applied Superconductivity, vol. 33, no. 4, pp. 1-11, June 2023, Art no. 1302711.


・Ikki Nagaoka, Ryota Kashima, Koki Ishida, Masamitsu Tanaka, Taro Yamashita, Takatsugu Ono, Koji Inoue, Akira Fujimaki,
“A High-Throughput Multiply-Accumulate Unit With Long Feedback Loop Using Low-Voltage Rapid Single-Flux Quantum Circuits”,
IEEE Transactions on Applied Superconductivity, vol. 33, no. 3, pp. 1-8, April 2023, Art no. 1301808.

2022年度

・Yuto Takeshita, Feng Li, Masayuki Higashi, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki,
“Direct observations of π-leaps of superconducting phase differences in π-junction-based SQUIDs”,
Supercond. Sci. Technol. 36, 045004 (2023).


・Duong Pham, Riku Sugimoto, Kenjiro Oba, Yuto Takeshita, Feng Li, Masamitsu Tanaka, Taro Yamashita, Akira Fujimaki,
“Weak spin-flip scattering in Pd89Ni11 interlayer of NbN-based ferromagnetic Josephson junctions”,
Scientific Reports volume 12, Article number: 6863 (2022).


・金 鮮美, 寺井 弘高, 山下 太郎, 猪股 邦宏
「結晶成長させた窒化物を用いた超伝導量子ビット」
日本物理学会誌「最近の研究から」、2022 年 77 巻 12 号 p. 805-810.