BCS-BEC Crossover in Mix-dimensional Fermi Gases

TL;DR

This paper studies the superfluid transition in a mix-dimensional Fermi gas, revealing how mass imbalance, lattice spacing, and polarization affect the transition temperature and superfluid stability across the BCS-BEC crossover.

Contribution

It introduces a detailed analysis of the BCS-BEC crossover in a mix-dimensional Fermi gas, including effects of noncondensed pairs and population imbalance.

Findings

Transition temperature decreases with increased mass imbalance.

Reducing lattice constant $dz$ lowers the transition temperature.

Superfluid stability is sharply destroyed by increased polarization.

Abstract

We investigate a mix-dimensional Fermi-Fermi mixture in which one species is confined in two-dimensional(2D) space while the other is free in three-dimensional space(3D). We determine the superfluid transition temperature $T_{c}$ for the entire BCS-BEC crossover including the important effects of noncondensed pairs. We find that the transition temperature reduces while the imbalance of mass is increased or lattice constant ($dz$) is reduced. In population imbalance case, the stability of superfluid is sharply destroyed by increasing the polarization.