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Finite-momentum bound pairs of two electrons in an altermagnetic metal

Hui Hu, Zhao Liu, Jia Wang, and Xia-Ji Liu

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Phys. Rev. B 114, 165124 – Published 16 September, 2026

DOI: https://doi.org/10.1103/whw7-hdtg

Abstract

We solve the two-electron problem on a square lattice with d-wave altermagnetism, considering both on-site and nearest-neighbor attractive interactions. The altermagnetic spin-splitting in the single-particle dispersion naturally gives rise to a ground state of two-electron bound pairs with nonzero center-of-mass momentum. The emergence of finite-momentum bound states suggests that altermagnetic spin splitting may favor pairing at nonzero center-of-mass momentum, which could be relevant for proposed Fulde-Ferrell-Larkin-Ovchinnikov superconductivity in altermagnetic systems. Additionally, when the nearest-neighbor attraction is strong, the resulting finite-momentum bound pairs exhibit a mixture of both spin-singlet and spin-triplet characteristics, suggesting the possibility of unconventional superconductors, where spin-singlet and spin-triplet pairings coexist.

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Outline

Information

Phys. Rev. B 114, 165124– Published 16 September, 2026
  • Received 19 January 2026
  • Revised 4 July 2026
  • Accepted 1 September 2026
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