Investigating Dirty Crossover through Fidelity Susceptibility and Density of States

Abstract

We investigate the BCS-BEC crossover in an ultracold atomic gas in the presence of disorder. The disorder is incorporated in the mean-field formalism through Gaussian fluctuations. We observe evolution to an asymmetric line-shape of fidelity susceptibility as a function of interaction coupling with increasing disorder strength which may point to an impending quantum phase transition. The asymmetric line-shape is further analyzed using the statistical tools of skewness and kurtosis. We extend our analysis to density of states (DOS) for a better understanding of the crossover in the disordered environment.