Giant field-free transverse Josephson diode effect in altermagnets

Bijay Kumar Sahoo; Abhiram Soori

doi:10.1103/ydrg-7spp

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arXiv · 2509.14109

Giant field-free transverse Josephson diode effect in altermagnets

Bijay Kumar Sahoo·Abhiram Soori

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Abstract

We predict a field-free transverse Josephson diode effect in altermagnets (AMs) with Rashba spin--orbit coupling, achieving diode efficiencies exceeding $3000\%$ and unidirectional transverse supercurrents in four-terminal junctions. In this geometry, a longitudinal phase bias generates transverse supercurrents that exhibit nonreciprocity and a finite anomalous phase shift, while the longitudinal current itself displays a Josephson diode effect. Both responses are tunable via the N\'eel vector orientation. We further show that the effect remains robust against moderate disorder and imperfect interfaces. These results establish AMs as a promising platform for nonreciprocal superconducting transport, with clear routes toward experimental realization.

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Bijay Kumar Sahoo, Abhiram Soori. 2025-09-17. Giant field-free transverse Josephson diode effect in altermagnets. https://doi.org/10.1103/ydrg-7spp

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