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arXiv · 2509.08262

Unconventional Josephson effects in {\it PT}-symmetric antiferromagnetic bilayers

Jin-Xin Hu·Mengli Hu·Ying-Ming Xie·K. T. Law
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Abstract

We propose that unconventional Josephson effects can typically emerge in {\it PT}-symmetric antiferromagnetic (AFM) bilayer systems. When proximitized by a conventional superconductor, these heterostructures host dominant interlayer Cooper pairing that features a distinctive spin texture enabled by the strong exchange field. Specifically, we demonstrate a novel mechanism for electrically tunable 0-$π$ oscillations in lateral Josephson junctions, controlled by an out-of-plane electric displacement field. This behavior originates from field-induced finite-momentum Cooper pairing, a hallmark of the unique layer-pseudospin structure in {\it PT}-symmetric AFM bilayers. Furthermore, we introduce a Josephson giant magnetoresistor based on these exotic spin-layer-locked Cooper pairs, in which the supercurrent exhibits a strong dependence on the internal Néel order. Our findings establish {\it PT}-symmetric AFM bilayers as a versatile platform for phase-controllable Josephson junctions and superconducting magnetic random-access memory, with promising applications in superconducting circuits and ultralow-power computing.

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Jin-Xin Hu, Mengli Hu, Ying-Ming Xie, K. T. Law. 2026-01-27. Unconventional Josephson effects in {\it PT}-symmetric antiferromagnetic bilayers. https://arxiv.org/abs/2509.08262

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