Updated on 2024/10/18

写真a

 
LI Feng
 
Organization
Graduate School of Engineering Electronics 3 Designated assistant professor
Title
Designated assistant professor

Research Areas 1

  1. Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Electron device and electronic equipment  / 超伝導デバイス、超伝導デジタル回路、超伝導量子ビット

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Research History 2

  1. Nagoya University   Designated assistant professor

    2022.4

  2. Nagoya University   Researcher

    2019.7 - 2022.3

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Education 2

  1. 中国科学院大学   上海微系统与信息技术研究所   固体電子学

    2014.9 - 2019.6

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    Country： China

  2. 青島大学   物理学部   材料物理研究科

    2010.9 - 2014.6

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    Country： China

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Professional Memberships 1

  1. 応用物理学会

    2020.3

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Awards 1

  1. 応用物理学会秋季学術講演会講演奨励賞

    2021.9   応用物理学会  

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    Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Papers 16

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

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

    Superconductor Science and Technology   Vol. 34 ( 2 )   2121.1

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    Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    DOI： https://doi.org/10.1088/1361-6668/abcaac

  2. Intrinsic superconducting phase battery Reviewed

    Li, F; Higashi, M; Sato, T; Tanaka, M; Fujimaki, A

    APPLIED PHYSICS LETTERS   Vol. 124 ( 22 )   2024.5

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    Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Applied Physics Letters  

    Leveraging the quantization properties inherent in superconductors, we present the development of an intrinsic superconducting phase battery. This advancement is achieved by integrating a ferromagnetic π-phase Josephson junction (π-JJ) within a superconducting ring. The core innovation lies in harnessing the potential energy of the π-JJ to generate an intrinsic circulating current, thereby inducing a phase difference as the current goes through the geometric inductance. This mechanism allows for tuning the phase bias φ (0 < φ < π) through an arrangement of the geometric inductance in the battery. We integrate the intrinsic phase batteries into superconducting quantum interference devices, where we verified the effectiveness of the induced phase bias. The polarity of the phase battery is determined by the direction of the intrinsic circulating current, which can be initialized by an external magnetic field. The design methodology for precise intrinsic phase bias has been established. Our findings not only show the feasibility of generating an intrinsic and adjustable phase bias using established fabrication techniques but also open new avenues for enhancing the design, efficiency, and functionality of superconducting electronics, promising to accelerate advancements in digital and quantum computing technologies.

    DOI： 10.1063/5.0212240

    Web of Science

    Scopus

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

    Pham, D; Li, F; Oba, K; Takeshita, Y; Tanaka, M; Yamashita, T; Fujimaki, A

    SUPERCONDUCTOR SCIENCE & TECHNOLOGY   Vol. 37 ( 5 )   2024.5

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    Language：English   Publishing type：Research paper (scientific journal)   Publisher：Superconductor Science and Technology  

    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.

    DOI： 10.1088/1361-6668/ad3c9c

    Web of Science

    Scopus

  4. Flux transfer circuits breaking conventional limit in transfer coefficient based on a negative inductance of a <i>π</i>-junction Reviewed

    Higashi, M; Li, F; Tanaka, M; Fujimaki, A

    SUPERCONDUCTOR SCIENCE & TECHNOLOGY   Vol. 37 ( 4 )   2024.4

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    Language：English   Publishing type：Research paper (scientific journal)   Publisher：Superconductor Science and Technology  

    We have demonstrated transfer coefficients breaking the conventional limit in flux transfer circuits (FTCs) by introducing a π-phase-shifted Josephson junction (π-junction), where the FTCs include an input/output inductor. According to the current-phase relationship of a π-junction, the π-junction behaves as an inductor with intrinsically negative kinetic inductance. When a single-π-junction superconducting quantum interference device (π-SQUID) in which a geometric inductor is placed in parallel with the π-junction is formed, a current flowing on the inductor, that is, the internal flux is increased against an input current or an input flux supplied externally to the π-SQUID in case that the π-SQUID shows no hysteresis in characteristics of internal-external flux. The FTC under investigation (π-FTC) is composed of two identical π-SQUIDs sharing a π-junction. The magnitude of the internal flux exceeds that of the external flux in the π-SQUID near zero external flux. Using this effect, the transfer coefficients are expected to be increased in the π-FTCs. Numerical analysis for π-FTCs reveals that the transfer coefficients exceed the conventional limit in a wide range of input currents corresponding to the input flux, although the negative kinetic inductance depends on the magnitude of the input. We made several π-FTCs for critical currents of the π-junctions of 50 πA and 60 πA. The output flux was measured by constructing a flux-locked loop. The experimentally obtained ratios of the transfer coefficients of the π-FTCs to the coefficient of the conventional FTC made on the same chip agree with the numerical results, which supports the negative kinetic inductances cause the increased coefficients breaking the conventional limit. Because the transfer coefficient is almost independent of input currents, we believe that the π-FTCs are applicable for strengthening not only couplings used in quantum annealers or SQUID sensors but also couplings used in superconductor digital circuits.

    DOI： 10.1088/1361-6668/ad2b79

    Web of Science

    Scopus

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

    Li, F; Pham, D; Takeshita, Y; Higashi, M; Yamashita, T; Tanaka, M; Fujimaki, A

    SUPERCONDUCTOR SCIENCE & TECHNOLOGY   Vol. 36 ( 10 )   2023.10

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    Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Superconductor Science and Technology  

    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 I cn 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.

    DOI： 10.1088/1361-6668/acf0f2

    Web of Science

    Scopus

  6. Analysis of the Effect of 0-π SQUIDs for Enhancing Mutual Coupling Invited Reviewed

    Higashi, M; Takeshita, Y; Kato, K; Fujisawa, H; Li, F; Tanaka, M; Yamashita, T; Fujimaki, A

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY   Vol. 33 ( 5 )   2023.8

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    Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE Transactions on Applied Superconductivity  

    This study shows that we can obtain an enhanced mutual coupling by using a superconducting quantum interference device (SQUID) containing a π-phase shift Josephson junction (π-junction). The π-junction can increase the current flowing in the loop inductance of the SQUID, thereby enhancing the magnetic flux generated in the inductance. Therefore, the effective self-inductance of the SQUID can increase, resulting in an increase in the mutual coupling. We use a 0-π SQUID formed by a conventional Josephson junction (0-junction) and a π-junction. Our numerical analysis for a simplified structure revealed that the ratio of effective to original self-inductance increased to 50. To confirm this, we measured the modulation patterns of critical current in dc-SQUIDs in which part of the loop inductance was replaced with a series of 0-π SQUIDs. The observed modulation pattern revealed that the effective self-inductance became more than 10-fold larger than the original self-inductance under the conditions that the applied current is a few μA while the critical current of the 0-junction in 0-π SQUIDs is 35 μA.

    DOI： 10.1109/TASC.2023.3249657

    Web of Science

    Scopus

  7. Optimization of Half-Flux-Quantum Circuits Composed of π-Shift and Conventional Josephson Junctions Reviewed

    Tanemura, S; Takeshita, Y; Li, F; Nakayama, T; Tanaka, M; Fujimaki, A

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY   Vol. 33 ( 5 )   2023.8

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    Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE Transactions on Applied Superconductivity  

    We report optimization of half-flux-quantum (HFQ) circuits composed of SQUIDs containing conventional Josephson junctions and π-shift magnetic Josephson junctions. The SQUID can act as a Josephson junction with an extremely small critical current and be easily switched by a weak driving force with the assistance of the circulating current that is induced due to the π-shift and quantization conditions. It leads to a drastic reduction of both static and dynamic power consumption. However, the parameter margins of the HFQ circuits obtained so far is narrow compared with conventional single-flux-quantum circuits. Since HFQ circuits use many circuit elements and require the two junctions in the SQUID to switch alternately and symmetrically, circuit parameter optimization is much more difficult. In this study, we developed an optimization tool for HFQ circuits, including operation judgment and margin calculation. We improved the critical margin of the HFQ Josephson transmission line to 39%. We also optimized the HFQ splitter, confluence buffer, and D flip-flop. We discuss design guidelines for HFQ circuits based on our systematic exploration of the optimized circuit parameter sets. We suggest that the optimized loop inductances are around 0.5 and 1.5 of Φ0/2 for data transmission and storage, respectively.

    DOI： 10.1109/TASC.2023.3258374

    Web of Science

    Scopus

  8. Superconductor digital circuits with π junctions alone Reviewed

    Li, F; Takeshita, Y; Tanaka, M; Fujimaki, A

    APPLIED PHYSICS LETTERS   Vol. 122 ( 16 )   2023.4

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    Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Applied Physics Letters  

    We adopt superconductor/ferromagnet/insulator/superconductor (SFIS) Josephson junctions (JJs) as both switching JJs and intrinsic πphase shifters in superconductor digital circuits. The critical current density (Jc) and characteristic voltage (Vc) of the SFIS junctions are about 22 A/cm2 and 22 μV, respectively. The intrinsic πphase shift is confirmed by measuring the suppressed nominal critical current Icn and half-period-shifted modulation pattern of a π-π-πsuperconducting quantum interference device (SQUID) that contains three π-JJs in a superconducting loop. A single-flux-quantum (SFQ) circuit composed of a DC/SFQ, Josephson transmission line (JTL), and SFQ/DC converter based on SFIS JJs alone is demonstrated at 4.2 K. The energy dissipation of the SFQ/DC converter decreases by 80% because some JJs are self-biased by the πphase shifter. The intrinsic circulating currents induced by the πphase shifters lead to a narrow bias margin (±5%) and even error function, which can be solved by parameters optimization or circuit initialization in the future. The half-modulation period (φ0/2) of a half-flux-quantum (HFQ) SQUID (a partial HFQ JTL) exhibits propagation of HFQ between π-π-πSQUIDs, indicating that more complex HFQ circuits can be developed with π-JJs alone in the future.

    DOI： 10.1063/5.0144604

    Web of Science

    Scopus

  9. Direct observations of π-leaps of superconducting phase differences in π-junction-based SQUIDs Reviewed

    Takeshita, Y; Li, F; Higashi, M; Tanaka, M; Yamashita, T; Fujimaki, A

    SUPERCONDUCTOR SCIENCE & TECHNOLOGY   Vol. 36 ( 4 )   2023.4

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    Language：English   Publishing type：Research paper (scientific journal)   Publisher：Superconductor Science and Technology  

    We directly observed π-leaps of superconducting phase differences in π-junction-based superconducting quantum interference devices (SQUIDs). The SQUIDs studied here are formed by introducing a π-junction to a conventional-junction (0-junction)-based direct current (DC)-SQUID, which is referred to as the 0-0-π SQUID. Either clockwise or counter-clockwise-circulating currents flow spontaneously in the 0-0-π SQUID because of a π-phase shift of the π-junction. In other words, the 0-0-π SQUID has a bistable state corresponding to the directions of circulating currents. π-leaps are generated by transiting between the two states of the bistable state. π-leaps are an ultra-fast phenomenon and are difficult to observe as they are. We prepared a half-flux quantum (HFQ)-SQUID that comprised two 0-0-π SQUIDs. π-leaps are reflected in a static characteristic, that is, a modulation pattern of the critical current in the HFQ-SQUID. We formed π-junctions with the PdNi layer on 0-junction-based circuits supplied by the National Institute of Advanced Industrial Science and Technology. The modulation pattern of the HFQ-SQUID had a period corresponding to π-leaps as expected, although some microstructures were observed. We demonstrated that the microstructures originated from the asymmetry inside each 0-0-π SQUID by analyzing the relationship between the phase change of 0-0-π SQUIDs and the modulation patterns.

    DOI： 10.1088/1361-6668/acb38d

    Web of Science

    Scopus

  10. Weak spin-flip scattering in Pd<sub>89</sub>Ni<sub>11</sub> interlayer of NbN-based ferromagnetic Josephson junctions Reviewed

    Pham, D; Sugimoto, R; Oba, K; Takeshita, Y; Li, F; Tanaka, M; Yamashita, T; Fujimaki, A

    SCIENTIFIC REPORTS   Vol. 12 ( 1 ) page： 6863   2022.4

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    Language：English   Publishing type：Research paper (scientific journal)   Publisher：Scientific Reports  

    We studied niobium nitride (NbN)-based π-junctions with a diluted ferromagnetic Pd89Ni11 interlayer (NbN/PdNi/NbN junctions). In the NbN/PdNi/NbN junctions with various PdNi thicknesses, we observed a non-monotonic dependence of the critical currents on PdNi thickness, indicating the effects of the exchange interaction on the superconducting order parameter. From theoretical fitting of the experimental data, we found that the NbN/PdNi/NbN junctions showed a significantly smaller degree of spin-flip scattering in the PdNi interlayer than in the CuNi interlayer of NbN/CuNi/NbN junctions reported previously. The weak spin-flip scattering leads to a longer decay length of the Josephson critical current, so the critical currents were observed over a wide range of PdNi thicknesses (10–40 nm). We also fabricated superconducting quantum interference devices (SQUIDs) including the NbN/PdNi/NbN junction, using a PdNi thickness in which the π-state was expected. A half-flux-quantum shift, as evidence of the π-state, was observed in the magnetic field-dependent critical currents of the SQUIDs. This result represents an important step towards the practical application of NbN-based π-Josephson junctions.

    DOI： 10.1038/s41598-022-10967-6

    Web of Science

    Scopus

    PubMed

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

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

    IEEE Transactions on Applied Superconductivity   Vol. 31 ( 5 )   2021.8

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    Language：English   Publishing type：Research paper (international conference proceedings)  

    DOI： https://doi.org/10.1109/tasc.2021.3060351

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

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

    IEEE Transactions on Applied Superconductivity   Vol. 31 ( 5 )   2021.8

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    Language：English   Publishing type：Research paper (international conference proceedings)  

    DOI： https://doi.org/10.1109/tasc.2021.3072846

  13. The 0– π Phase Transition in Epitaxial NbN/Ni 60 Cu 40 /NbN Josephson Junctions Reviewed

    Feng Li, Wei Peng, Zhen Wang

    Chinese Physics Letters   Vol. 36 ( 4 )   2019.4

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    Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

    DOI： https://doi.org/10.1088/0256-307x/36/4/047401

  14. Measurement of the intrinsic higher harmonic current-phase relation in NbN/NiCu/NbN Josephson junctions Reviewed

    Feng Li, Long Wu, Lei Chen, Shenqiu Zhang, Wei Peng, Zhen Wang

    Physical Review B   Vol. 99 ( 10 )   2019.3

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    Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

    DOI： https://doi.org/10.1103/physrevb.99.100506

  15. Fabrication of Three-Dimensional Nanobridge Junction Arrays for SQIFs Reviewed

    Xiaolei Wu, Lei Chen, Hao Wang, Long Wu, Feng Li, Xiaoyu Liu, Zhen Wang

    IEEE Transactions on Applied Superconductivity   Vol. 28 ( 4 )   2018.6

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    Language：English   Publishing type：Research paper (international conference proceedings)  

    DOI： https://doi.org/10.1109/tasc.2018.2803108

  16. Ferromagnetic Josephson junctions based on epitaxial NbN/Ni60Cu40/NbN trilayer Reviewed

    Feng Li, Hui Zhang, Lu Zhang, Wei Peng, Zhen Wang

    AIP Advances   Vol. 8 ( 5 )   2018.5

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    Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

    DOI： https://doi.org/10.1063/1.5030348

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Presentations 21

  1. Field Free Superconducting Diode Effect with π-JJ-based Arbitrary Phase Shifter” International conference

    F. Li, T. Sato, H. Fujisawa, M. Higashi, Y. Takeshita, M. Tanaka, A. Fujimaki

    16th European Conference on Applied Superconductivity (EUCAS 2023)   2023.9 

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    Presentation type：Oral presentation (general)  

    Country：Italy  

  2. 接合を用いた任意位相器に基づく超伝導ダ イオードの実証

    李 峰, 佐藤 太一, 藤澤 日, 向, 竹下 雄登, 田中 雅光, 藤巻 朗

    第70 回応用物理学会秋季学術講演 会 2023年  2024.9  応用物理学会

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    Presentation type：Oral presentation (general)  

  3. Energy Efficient Half-flux-quantum Circuit Aiming at Milli-kelvin Stage Operation International conference

    F. Li , D. Pham , Y. Takeshita , S. Tanemura , M. Higashi , M. Tanaka , A. Fujimaki

    The 18th International Superconductive Electronics Conference (ISEC 2023)  2023.11 

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    Presentation type：Oral presentation (general)  

  4. 接合を用いた超伝導全波整流器の実証

    李 峰, 東正志, 佐藤太一, 竹下雄登, 田中雅光, 藤巻朗

    第84 回応用物理学会秋季学術講演 会 2023年  2023.3  応用物理学会

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    Presentation type：Oral presentation (general)  

  5. A Compact Giant Inductance Device Based on the Negative Flowing Current Across the Ferromagnetic Josephson Junction for Superconducting Electronics Invited International conference

    F. Li, M, Higashi, Y. Takeshita, M. Tanaka, and A, Fujimaki

    International Forum on Applied Superconductivity and Magnetism (IFASM Oceania 2022)   2022.12 

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    Presentation type：Oral presentation (invited, special)  

    Country：Australia  

  6. π-π-π SQUIDs: The Switching Element of HFQ Circuits Operating at mK Invited

    2022.3 

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    Presentation type：Oral presentation (invited, special)  

  7. The Power Efficient Half-Flux-Quantum Circuits based on π-π-π SQUIDs Aiming at the Control of Qubit Circuits at 10 mK Stage International conference

    F. Li, D. Pham, Y. Takeshita, M. Higashi, M. Tanaka, T, Yamashita, A. Fujimaki

    Applied Superconductivity Conference (ASC 2022)   2022.9 

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    Presentation type：Poster presentation  

    Country：United States  

  8. 公開 A Giant Inductance Device Based on the Negative Flowing Current Across the Ferromagnetic Josephson Junction for Superconducting Electronics International conference

    F. Li, M. Higashi, Y. Takeshita, M. Tanaka, T. Yamashita, and A, Fujimaki

    The 15th Superconducting SFQ VLSI Workshop (SSV 2022) / 4th Workshop on Quantum and Classical Cryogenic Devices, Circuits, and Systems (QCCC 2022)  2022.10 

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    Presentation type：Oral presentation (general)  

    Country：Japan  

  9. Half-Flux-Quantum T-Flip Flops Based on π-π-π SQUIDs

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    Country：Japan  

  10. Half-flux-quantum Circuits Using π-shifted Ferromagnetic Junctions Invited International conference

    F. Li, Y. Takeshita, M, Higashi, M. Tanaka, T. Yamashita, A. Fujimaki

    The 34th International Symposium on Superconductivity (ISS 2021)  2021.11 

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    Presentation type：Oral presentation (invited, special)  

  11. Low-power Half-flux-quantum Circuits and the Fabrication Process Based on Ferromagnetic SFIS Josephson Junctions International conference

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

    The 14th Superconducting SFQ VLSI Workshop (SSV 2021) / 3rd Workshop on Quantum and Classical Cryogenic Devices, Circuits, and Systems (QCCC 2021)  2021.10 

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    Presentation type：Oral presentation (general)  

    Country：Japan  

  12. Demonstration of Half-Flux-Quantum T-Flip Flops Made up with Only π Junctions International conference

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

    15th European Conference on Applied Superconductivity (EUCAS 2021)  2021.9 

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    Presentation type：Poster presentation  

  13. Demonstration of π-junction-based SQUIDs with Half-flux-quantum Modulation Periods for Energy-efficient Circuits International conference

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

    Applied Superconductivity Conference (ASC 2020)  2020.9 

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    Presentation type：Oral presentation (general)  

    Country：United States  

  14. Simulation and Comparison of the Energy Efficiency of Half Flux Quantum Circuits International conference

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

    13th Superconducting SFQ VLSI Workshop (SSV 2020) / 2nd Workshop on Quantum and Classical Cryogenic Devices, Circuits, and Systems (QCCC 2020)  2020.1 

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    Presentation type：Poster presentation  

    Country：Japan  

  15. Energy Consumption of Half Flux Quantum Circuits Using π-shifted Josephson Junctions International conference

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

    The 32nd International Symposium on Superconductivity (ISS 2019)  2019.11 

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    Presentation type：Poster presentation  

    Country：Japan  

  16. The Intrinsic Second Harmonic CPR in Ferromagnetic Josephson Junctions

    F. Li, W. Peng, Z. Wang

    1st Workshop on Quantum and Classical Cryogenic Devices, Circuits, and Systems (QCCC 2019)  2019.10 

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    Presentation type：Oral presentation (general)  

    Country：Japan  

  17. π Josephson Junction in Epitaxial NbN/Ni60Cu40/NbN Structure International conference

    F. Li, W. Peng, Z Wang

    12th Superconducting SFQ VLSI Workshop (SSV 2019)  2019.1 

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    Presentation type：Oral presentation (general)  

  18. Fabrication and Characterization of NbN-based Magnetic Josephson Junctions International conference

    F. Li, W. Peng, Z. Wang

    12th International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors (M2S-2018)  2018.12 

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    Presentation type：Poster presentation  

  19. 0-π Phase State in NbN/NiCu/NbN Magnetic Josephson Junctions International conference

    F. Li, W. Peng, Z, Wang

    Applied Superconductivity Conference (ASC 2018)  2018.9 

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    Presentation type：Poster presentation  

  20. Magnetic Josephson Junctions Based on NbN/NiCu/NbN Trilayer International conference

    F. Li, W. Peng, Z. Wang

    13th European Conference on Applied Superconductivity (EUCAS 2017)  2017.9 

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    Presentation type：Poster presentation  

    Country：Switzerland  

  21. SFIS磁性π接合に基づくアンシャントSFQ回路の特性評価

    李峰, 袁磊, 竹下雄登, 東正志, 田中雅光, 藤巻朗

    第83 回応用物理学会秋季学術講演  2022.9 

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    Presentation type：Oral presentation (general)  

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KAKENHI (Grants-in-Aid for Scientific Research) 2

  1. Giant Inductance Device based on Ferromagnetic pi Josephson Junctions for Increasing the Integration of Superconductor Digital Circuits

    Grant number：23K13376  2023.4 - 2025.3

    科学研究費助成事業  若手研究

    李 峰

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    Authorship：Principal investigator 

    Grant amount：\4680000 （ Direct Cost: \3600000 、 Indirect Cost：\1080000 ）

    本研究では、磁性ジョセフソン接合による負性インダクタンス素子を実現し、これを超伝導線と並列接続することで超伝導巨大インダクタンス素子（π-SQUID）を実現したことである。π-SQUIDの実効インダクタンスは、幾何学的インダクタンスのみの場合よりも数十倍倍以上であり、π-SQUIDの設計方法論を確定し、デバイスの製造プロセスを最適化し、共振測定によってデバイスの有効インダクタンスを検出し、それを超伝導デジタル回路の統合度向上に応用することです。

  2. Research on Intrinsic Mechanism of True Random Number Generation for Absolutely Secure Communications by Using Half Flux Quantum Circuit

    Grant number：20K22412  2020.9 - 2022.3

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    Authorship：Principal investigator  Grant type：Competitive

    Grant amount：\2860000 （ Direct Cost: \2200000 、 Indirect Cost：\660000 ）

To the head of KAKENHI (Grants-in-Aid for Scientific Research).▲

Industrial property rights 2

  1. 约瑟夫森结结构、存储单元、存储单元阵列及制备方法

    李　峰，彭 炜，王 镇

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    Applicant：中国科学院上海微系统与信息技术研究所

    Announcement no：CN 108364951 B 

  2. 超伝導位相シフタ、超伝導位相シフタ素子、ダイオード素子および整流器

    李　峰，田中　雅光，藤巻　朗

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    Applicant：国立大学法人東海国立大学機構

    Application no：2024-013168 

To the head of Industrial property rights.▲
 

Academic Activities 1

  1. 雑誌のレビュアー International contribution

    Role(s)：Peer review

    1. Superconductor Science and TechnologyとQuantum Science and TechnologyとSuperconductivity 

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    Type：Peer review 

To the head of Academic Activities.▲