Low temperature properties of the fermionic mixtures with mass imbalance in optical lattice

TL;DR

This paper investigates the low temperature phases of mass-imbalanced fermionic mixtures in optical lattices using advanced computational methods, revealing a supersolid state where superfluidity and density wave order coexist.

Contribution

It combines dynamical mean-field theory with quantum Monte Carlo to analyze phase competition and maps the phase diagram for mass-imbalanced fermionic systems.

Findings

Identification of a supersolid phase with coexisting orders

Phase diagram showing competition between superfluid and density wave states

Degeneracy of superfluid and density wave states at half filling

Abstract

We study the attractive Hubbard model with mass imbalance to clarify low temperature properties of the fermionic mixtures in the optical lattice. By combining dynamical mean-field theory with the continuous-time quantum Monte Carlo simulation, we discuss the competition between the superfluid and density wave states at half filling. By calculating the energy and the order parameter for each state, we clarify that the coexisting (supersolid) state, where the density wave and superfluid states are degenerate, is realized in the system. We then determine the phase diagram at finite temperatures.