While a spin-dependent band splitting is one of the characteristic features of altermagnets, the conventional band picture itself breaks down in the many altermagnets that are correlated Mott materials. We thus investigate the so far less explored strong-coupling limit. Employing numerical many-body methods (the self-consistent Born approximation and a variational cluster approach), we find that spin-dependent spectral-weight transfer is the dominant signature of Mott altermagnetism, rather than band splitting. We demonstrate this effect by calculating angle-resolved photoemission spectroscopy spectra for three canonical altermagnetic systems: the checkerboard J-J' model, a variant describing the transition-metal–ion sites of the inverse Lieb lattice, and the Kugel-Khomskii spin-orbital altermagnet based on cubic vanadates RVO3 (R=La , Pr, Nd, Y). This pronounced spin–momentum locking of the quasiparticle spectral weight arises the interplay between free hole motion and the coupling of the hole to magnon excitations in the altermagnet [1}.

We then investigate how altermagnetism affects the interaction between holes doped into strong-coupling altermagnets. Starting from antiferromagnetism, where this questions has been intensely studied in the context of cuprates, we explore the impact of altermagnetic symmetries.

[1] M. Daghofer, K. Wohlfeld, J. van den Brink, Phyy. Rev. Lett. 136, 146502 (2026)