Mixed phases in a Fermi--Hubbard model describing altermagnetism

E. Langmann; J. Lenells

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arXiv · 2506.16503

Mixed phases in a Fermi--Hubbard model describing altermagnetism

E. Langmann·J. Lenells

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Abstract

We study an extension of the 2D Fermi--Hubbard model, which was recently introduced in [Das et al., Phys. Rev. Lett. 132, 263402 (2024)] and shown to describe altermagnetism that can be studied in cold atom systems. Using an updated Hartree--Fock method that can detect instabilities towards phase separation, we show that the model is in a mixed phase in large parts of the parameter regime at half-filling. We argue that the occurrence of a mixed phase is an indication of exotic physics which, in this model, occurs in parameter regimes accessible in cold atom experiments.

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E. Langmann, J. Lenells. 2025-06-19. Mixed phases in a Fermi--Hubbard model describing altermagnetism. https://arxiv.org/abs/2506.16503

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