Flat-band-induced non-Fermi-liquid behavior of multicomponent fermions

Abstract

We investigate multicomponent fermions in a flat band and predict experimental signatures of non-Fermi-liquid behavior. We use dynamical mean-field theory to obtain the density, double occupancy and entropy in a Lieb lattice for N = 2 and N = 4 components. We derive a mean-field scaling relation between the results for different values of N, and study its breakdown due to beyond mean-field effects. The predicted signatures occur at temperatures above the Néel temperature and persists even in the presence of a trapping potential, thus they are observable in current ultracold gas experiments.