Anomalous dispersion of the collective modes of an ultracold $^6Li-$ $^{40}K$ mixture in a square optical lattice

摘要: We report numerical calculations of the collective excitation spectrum and speed sound superfluid phase an atomic Fermi-Fermi mixture population-imbalanced Lithium-6 Potassium-40 atoms in a square lattice. It is predicted that exotic states matter, known as Fulde-Ferrell phase, anomalous dispersion modes may be realized at some values polarization, interacting strength temperature, i.e. collective-mode initially bends upward before bending over quasimomentum increases.