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Orientation-dependent exceptional points in non-Hermitian altermagnetic Josephson junctions

Mohammad Alipourzadeh1, Jamal Berakdar2, Wolfgang Belzig3, and Yaser Hajati1,2,3

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Phys. Rev. B 114, 074503 – Published 13 August, 2026

DOI: https://doi.org/10.1103/7wps-4ryn

Abstract

Motivated by the orientation-dependent spin splitting and vanishing net magnetization of altermagnets, we study d-wave altermagnetic Josephson junctions (JJs) with a focus on the emergence and controllability of non-Hermitian degeneracies [or exceptional points (EPs)] where both eigenvalues and eigenvectors coalesce. Unlike conventional JJs, the altermagnetic order induces spin- and orientation-dependent Andreev bound states, offering additional control of the Josephson effect. We show that the position of EPs as a function of the superconducting phase difference ϕ can be tuned by the crystal orientation, strength of the altermagnetic order, Rashba spin-orbit coupling, and the degree of non-Hermiticity. Furthermore, the number of EPs is found to be directly tunable by altermagnetic properties. The total supercurrent associated with different transverse momentum ky shows a smooth behavior but sensitive to the crystal orientation and other properties of the altermagnetic JJ. These findings demonstrate a pathway to realizing distinctive non-Hermitian phenomena arising from the interplay among non-Hermiticity, Rashba interaction, superconductivity, and altermagnetism.

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Phys. Rev. B 114, 074503– Published 13 August, 2026
  • Received 2 March 2026
  • Revised 11 June 2026
  • Accepted 17 June 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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