Dynamical response of ultracold interacting fermion-boson mixtures

TL;DR

This paper investigates the dynamical response of ultracold fermion-boson mixtures under strong coupling, revealing a pseudogap formation through advanced theoretical and computational methods.

Contribution

It introduces a non-perturbative analysis of the optical response of ultracold mixtures using diagrammatic resummation and quantum Monte Carlo simulations.

Findings

Identification of a pseudogap in the spectral function.

Calculation of optical conductivity in strong coupling regimes.

Application of diagrammatic and Monte Carlo methods to ultracold gases.

Abstract

We analyze the dynamical response of a ultracold binary gas mixture in presence of strong boson-fermion couplings. Mapping the problem onto that of the optical response of a metal/semiconductor electronic degrees of freedom to electromagnetic perturbation we calculate the corresponding dynamic linear response susceptibility in the non-perturbative regimes of strong boson-fermion coupling using diagrammatic resummation technique as well as quantum Monte Carlo simulations. We evaluate the Bragg spectral function as well as the optical conductivity and find a pseudogap, which forms in certain parameter regimes.