Zero-field superconducting diode effect induced by magnetic flux in a van der Waals superconductor trigonal PtBi$_2$

Nan Jiang; Masaki Maeda; Yuhi Yamaguchi; Mori Watanabe; Masashi Tokuda; Kensuke Takaki; Sebun Masaki; Takumi Ikushima; Takayoshi Koyanagi; Masakazu Matsubara; Kazutaka Kudo; Yasuhiro Niim

doi:10.1103/7knf-fm7x

arXiv · 2512.05427

Zero-field superconducting diode effect induced by magnetic flux in a van der Waals superconductor trigonal PtBi$_2$

Nan Jiang·Masaki Maeda·Yuhi Yamaguchi·Mori Watanabe·Masashi Tokuda·Kensuke Takaki·Sebun Masaki·Takumi Ikushima·Takayoshi Koyanagi·Masakazu Matsubara·Kazutaka Kudo·Yasuhiro Niim

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Abstract

The superconducting diode effect is one of the nonreciprocal transport phenomena, where the critical current depends on the current direction. This effect is typically realized in superconductors with broken spatial-inversion and time-reversal symmetry. To break the time-reversal symmetry, external magnetic fields are commonly used. Here, we demonstrate a sign-controllable superconducting diode effect under zero external magnetic field in a van der Waals superconductor trigonal PtBi$_2$. The sign of the zero-field superconducting diode effect is controlled by the poling magnetic field, that is a large magnetic field applied prior to measurements. This result indicates that trapped magnetic flux are responsible for breaking the time-reversal symmetry. Our findings highlight the crucial role of trapped magnetic flux in generating the superconducting diode effect and provide a general pathway for realizing a zero-field superconducting diode effect.

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Nan Jiang, Masaki Maeda, Yuhi Yamaguchi, Mori Watanabe, Masashi Tokuda, Kensuke Takaki, Sebun Masaki, Takumi Ikushima, Takayoshi Koyanagi, Masakazu Matsubara, Kazutaka Kudo, Yasuhiro Niim. 2025-12-05. Zero-field superconducting diode effect induced by magnetic flux in a van der Waals superconductor trigonal PtBi$_2$. https://doi.org/10.1103/7knf-fm7x

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