Supersolid state in fermionic optical lattice systems

TL;DR

This paper investigates the stability of a supersolid state in ultracold fermionic atoms within optical lattices, revealing the crucial role of harmonic confinement in stabilizing coexistence of superfluidity and density-wave order.

Contribution

It introduces a combined real-space dynamical mean-field theory approach with a two-site impurity solver to analyze supersolid phases in confined fermionic lattice systems.

Findings

Harmonic confinement stabilizes the supersolid state.

Phase diagrams show coexistence of superfluid and density-wave order.

Supersolid stability depends on effective particle density.

Abstract

We study ultracold fermionic atoms trapped in an optical lattice with harmonic confinement by combining the real-space dynamical mean-field theory with a two-site impurity solver. By calculating the local particle density and the pair potential in the systems with different clusters, we discuss the stability of a supersolid state, where an s-wave superfluid coexists with a density-wave state of checkerboard pattern. It is clarified that a confining potential plays an essential role in stabilizing the supersolid state. The phase diagrams are obtained for several effective particle densities.