Phase diagram of SU(3) Fermi gases with population imbalance in square optical lattices

Ultracold alkaline-earth(-like) atoms in optical lattices represent an ideal platform to study SU(N) magnetism. Recently, short-range SU(N > 2) magnetic correlations have been observed in ¹⁷³Yb systems [1,2]. Here we focus on the magnetic orderings in three-component SU(3) Fermi gases loaded into a square optical lattice. Previous studies have suggested that the ground state of the equally populated system has a three-sublattice stripe order [3]. We consider the case with population imbalance between one component and the others. In general, reducing the symmetry with population imbalance is expected to lead to exotic orders and phase transition phenomena [4]. We discuss the low-temperature properties and the thermal phase transition phenomena using the linear flavor-wave theory and semiclassical Monte Carlo method, respectively. Several magnetic states arise from the competition between antiferromagnetic interactions and population imbalance, including a peculiar partially-disordered state with checkerboard long-range order.

[1] H. Ozawa et al., Phys. Rev. Lett. 121, 225303 (2018).
[2] S. Taie et al., arXiv:2010.07730 (2020).
[3] T. A. Toth et al., Phys. Rev. Lett. 105, 265301 (2010).
[4] D. Yamamoto et al., Phys. Rev. Lett. 125, 057204 (2020).