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arXiv · 2505.20598

Interferometric evidence of non-volatile anomalous phase shifts in exchange-spin-split Josephson supercurrent diodes

Kun-Rok Jeon·Jae-Keun Kim·Jiho Yoon·Jae-Chun Jeon·Hyeon Han·Audrey Cottet·Takis Kontos·Stuart S. P. Parkin
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Abstract

The recent realization of zero-field, polarity-reversible supercurrent rectification in proximity-magnetized Rashba-type Pt Josephson junctions (JJs) enables the development of superconducting logic circuits and cryogenic memory applications. Here, we demonstrate a non-volatile anomalous phase shift ϕ_0 directly probed via superconducting quantum interferometry, providing phase-sensitive evidence of spontaneous time-reversal symmetry breaking in these Rashba-type systems. By replacing the Pt barrier with 5d or 4d element layers exhibiting different (para-)magnetic susceptibilities, spin-orbit coupling strengths, and electronic band structures, we elucidate the role of proximity effects in governing zero-field diode behavior. Ta (W) JJs exhibit zero-field diode efficiencies of ~17% (~5%) at 2 K, which are slightly (significantly) lower than those of Pt JJs. Notably, the diode polarity in Ta and W JJs is reversed relative to Pt JJs. Combined with the large zero-field diode efficiency (~15% at 2 K) observed in highly magnetic-susceptible Pd JJs, these results show that non-volatile ϕ_0 and, consequently, zero-field diode performance can be tuned through proximity engineering of interfacial magnetic ordering and Rashba spin-orbit interaction.

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Kun-Rok Jeon, Jae-Keun Kim, Jiho Yoon, Jae-Chun Jeon, Hyeon Han, Audrey Cottet, Takis Kontos, Stuart S. P. Parkin. 2026-06-23. Interferometric evidence of non-volatile anomalous phase shifts in exchange-spin-split Josephson supercurrent diodes. https://doi.org/10.1021/acsnano.5c17979

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