Magnetization and Josephson current coupling drives the Josephson diode effect in FeTe0.55Se0.45 van der Waals junctions
Abstract
The Josephson diode effect (JDE) reflects symmetry breaking in the current-phase relation (CPR) of Josephson junctions, yet establishing its microscopic origin is often challenging. We investigate the mechanism of the JDE in van der Waals Josephson junctions based on FeTe0.55Se0.45, a platform where superconductivity, topology, and magnetism may coexist at the interface. Our devices exhibit a robust zero-field diode response with asymmetric switching currents. Magnetic-field measurements reveal a hysteretic Fraunhofer pattern and magnetic-resonance-induced voltage feature, evidencing interfacial magnetism coupled to the Josephson current. Microwave response further shows half-integer Shapiro steps with asymmetric evolution, demonstrating contributions from both a second harmonic and a magnetization-induced phase shift in CPR. Numerical simulations combining magnetization dynamics and Josephson phase dynamics reproduce these features, confirming that the JDE originates from interfacial coupling between magnetization and Josephson current. This work provides a transport-based route to pinpoint the microscopic mechanism of the JDE, establishing a platform for exploring magnetically active interfacial superconductivity, and enables the design of nonreciprocal superconducting devices in clean, interface-engineered van der Waals systems.
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BibTeX
@misc{shin2026magnetization,
title = {{Magnetization and Josephson current coupling drives the Josephson diode effect in FeTe0.55Se0.45 van der Waals junctions}},
author = {Seung-Hyun Shin and Cheong-Eung Ahn and Chang-Won Choi and Taekoo Oh and Si-Young Choi and Genda Gu and Gil Young Cho and Gil-Ho Lee},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.29124},
eprint = {2610.29124},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.29124},
}
RIS
TY - UNPB
TI - Magnetization and Josephson current coupling drives the Josephson diode effect in FeTe0.55Se0.45 van der Waals junctions
AU - Seung-Hyun Shin
AU - Cheong-Eung Ahn
AU - Chang-Won Choi
AU - Taekoo Oh
AU - Si-Young Choi
AU - Genda Gu
AU - Gil Young Cho
AU - Gil-Ho Lee
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2610.29124
UR - https://arxiv.org/abs/2610.29124
AB - The Josephson diode effect (JDE) reflects symmetry breaking in the current-phase relation (CPR) of Josephson junctions, yet establishing its microscopic origin is often challenging. We investigate the mechanism of the JDE in van der Waals Josephson junctions based on FeTe0.55Se0.45, a platform where superconductivity, topology, and magnetism may coexist at the interface. Our devices exhibit a robust zero-field diode response with asymmetric switching currents. Magnetic-field measurements reveal a hysteretic Fraunhofer pattern and magnetic-resonance-induced voltage feature, evidencing interfacial magnetism coupled to the Josephson current. Microwave response further shows half-integer Shapiro steps with asymmetric evolution, demonstrating contributions from both a second harmonic and a magnetization-induced phase shift in CPR. Numerical simulations combining magnetization dynamics and Josephson phase dynamics reproduce these features, confirming that the JDE originates from interfacial coupling between magnetization and Josephson current. This work provides a transport-based route to pinpoint the microscopic mechanism of the JDE, establishing a platform for exploring magnetically active interfacial superconductivity, and enables the design of nonreciprocal superconducting devices in clean, interface-engineered van der Waals systems.
ER -