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arXiv · 2506.17651

Field-Free Superconducting Diode Enabled by Geometric Asymmetry and Perpendicular Magnetization

Jiaxu Li·Zijian Zhang·Shiqi Wang·Yu He·Haochang Lyu·Qiusha Wang·Bowen Dong·Daoqian Zhu·Hisakazu Matsuki·Dapeng Zhu·Guang Yang·Weisheng Zhao
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Abstract

The superconducting diode effect (SDE)- manifested as directional, dissipationless supercurrents - is pivotal for realizing energy-efficient superconducting logic and memory technologies. Achieving high-efficiency SDE without external magnetic fields, however, remains a fundamental challenge. Here, we report a strongly enhanced, field-free SDE in Pt/Co/Nb heterostructures, enabled by the interplay of engineered geometric asymmetry and stray fields from a perpendicularly magnetized Co layer. This configuration promotes directional vortex entry and spatially selective pinning, yielding diode efficiencies that exceed all previously reported field-free values. Temperature- and field-dependent transport measurements, supported by micromagnetic simulations, reveal that the enhanced nonreciprocity stems from three cooperative mechanisms: asymmetric vortex entry, localized magnetic pinning, and Lorentz-force imbalance. These findings establish a scalable, CMOS-compatible platform for high-performance superconducting rectifiers, offering new opportunities for cryogenic spintronics and quantum electronics.

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Jiaxu Li, Zijian Zhang, Shiqi Wang, Yu He, Haochang Lyu, Qiusha Wang, Bowen Dong, Daoqian Zhu, Hisakazu Matsuki, Dapeng Zhu, Guang Yang, Weisheng Zhao. 2025-10-22. Field-Free Superconducting Diode Enabled by Geometric Asymmetry and Perpendicular Magnetization. https://arxiv.org/abs/2506.17651

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