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arXiv · 2502.13391

Tunable superconducting diode effect in higher-harmonic InSb nanosheet interferometers

Xingjun Wu·Ji-Yin Wang·Haitian Su·Shili Yan·Dong Pan·Jianhua Zhao·Po Zhang·H. Q. Xu
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Abstract

Superconducting diodes, characterized by the nonreciprocal supercurrent flow, have gained significant attention for their potential in dissipationless electronics. This study presents a superconducting quantum interference device (SQUID) composed of two Al-InSb nanosheet Josephson junctions. Utilizing prepatterned local backgates, we achieve a gate- and flux-tunable superconducting diode with controllable efficiency in both amplitude and sign. Numerical simulations attribute the diode effect to higher harmonics in the current-phase relation. Crucially, fractional Shapiro step experiments provide direct insights into the evolution of these higher harmonics with flux tuning, showcasing significant enhancements in the second-harmonic signatures of the SQUID near half-integer flux quanta. Furthermore, we investigate the microwave-assisted diode response and experimentally show that the polarity of the diode effect can be switched by the microwave power. These results demonstrate the potential of InSb nanosheet-based hybrid devices as highly tunable elements for use in dissipationless electronics.

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Xingjun Wu, Ji-Yin Wang, Haitian Su, Shili Yan, Dong Pan, Jianhua Zhao, Po Zhang, H. Q. Xu. 2025-02-19. Tunable superconducting diode effect in higher-harmonic InSb nanosheet interferometers. https://doi.org/10.1088/1367-2630%2Fadb6ce

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