Linear Flavor-Wave Analysis of SU(4)-Symmetric Tetramer Model with Population Imbalance

We study the quantum magnetism of SU(4) Mott insulator in a square optical superlattice, which atoms with four nuclear-spin components strongly interact each other, presence an external field that controls imbalance between population two and other two. This is natural extension physics spin-dimer materials under strong magnetic field. apply extended linear flavor-wave theory based on four-site plaquettes unveil ground-state phase diagram excitation spectra. When balanced plaquesttes are weakly coupled, ground state approximately given by direct product local SU(4)-singlet states. In high-field, system reaches "saturated state" where only present. Our main finding nontrivial intermediate phase, has checkerboard-like arrangement resonating-valence-bond