Spontaneous altermagnetism in multi-orbital correlated electron systems

Fuente: arXiv
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Main Authors: Kaushal, Nitin, Patri, Adarsh S., Franz, Marcel
Format: Preprint
Published: 2026
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author Kaushal, Nitin
Patri, Adarsh S.
Franz, Marcel
author_facet Kaushal, Nitin
Patri, Adarsh S.
Franz, Marcel
contents Altermagnets have attracted considerable attention in recent years owing to their potential technological applications in spintronics and magnonics. Recently, a new class of spontaneous altermagnets has been theoretically predicted in a correlated two orbital model, driven by the coexistence of antiferromagnetic spin and staggered orbital ordering, thus broadening the scope of altermagnetic phenomena to systems with strong correlations. It has been noted, however, that the required spin and orbital order violates the well-established Goodenough-Kanamori (GK) rules, which underlie much of our understanding of magnetism in complex systems. Here we show that materials with three active orbitals may offer a more realistic route to this exotic state. Specifically, we consider a two-dimensional system with $t_{2g}^{2}$ electrons and identify a novel microscopic mechanism that allows the formation of a spontaneous altermagnetic Mott insulator. We explain how the GK rules are circumvented and provide the stability criteria by employing unbiased mean-field and density matrix renormalization group calculations. In addition, for the first time, we uncover the presence and microscopic origin of chirally split magnons in these spontaneous altermagnets, with experimentally measurable spin conductivities. Finally, we predict that the application of a small in-plane magnetic field induces, in the presence of weak atomic spin-orbit coupling, an as-yet unreported hybrid chiral magnon-orbiton mode with a non-zero orbital polarization giving rise to finite longitudinal and transverse orbital conductivities under a thermal gradient.
format Preprint
id arxiv_https___arxiv_org_abs_2602_23522
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Spontaneous altermagnetism in multi-orbital correlated electron systems
Kaushal, Nitin
Patri, Adarsh S.
Franz, Marcel
Strongly Correlated Electrons
Altermagnets have attracted considerable attention in recent years owing to their potential technological applications in spintronics and magnonics. Recently, a new class of spontaneous altermagnets has been theoretically predicted in a correlated two orbital model, driven by the coexistence of antiferromagnetic spin and staggered orbital ordering, thus broadening the scope of altermagnetic phenomena to systems with strong correlations. It has been noted, however, that the required spin and orbital order violates the well-established Goodenough-Kanamori (GK) rules, which underlie much of our understanding of magnetism in complex systems. Here we show that materials with three active orbitals may offer a more realistic route to this exotic state. Specifically, we consider a two-dimensional system with $t_{2g}^{2}$ electrons and identify a novel microscopic mechanism that allows the formation of a spontaneous altermagnetic Mott insulator. We explain how the GK rules are circumvented and provide the stability criteria by employing unbiased mean-field and density matrix renormalization group calculations. In addition, for the first time, we uncover the presence and microscopic origin of chirally split magnons in these spontaneous altermagnets, with experimentally measurable spin conductivities. Finally, we predict that the application of a small in-plane magnetic field induces, in the presence of weak atomic spin-orbit coupling, an as-yet unreported hybrid chiral magnon-orbiton mode with a non-zero orbital polarization giving rise to finite longitudinal and transverse orbital conductivities under a thermal gradient.
title Spontaneous altermagnetism in multi-orbital correlated electron systems
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2602.23522