Heteronuclear Cooper Pairs in An Ultracold Atomic Gas

TL;DR

This paper explores the formation of heteronuclear Cooper pairs in ultracold atomic gases, highlighting how mass differences and density imbalances affect pairing and superfluidity.

Contribution

It introduces the concept of heteronuclear pairing in ultracold gases with mass and density imbalances, expanding understanding of superfluidity in mixed atomic systems.

Findings

Pairing occurs between different atomic species with significant mass differences.

The pairing gap decreases with increasing density imbalance.

Superfluidity vanishes beyond a critical density difference.

Abstract

In an ultracold mixture of two different Fermi species of atoms, Cooper pairs can be formed between two different atoms. The masses of one atom and its partner in this kind of Cooper pairs may differ by order of magnitude. In this system, each species of atoms are in the same atomic spin state and two species have the same atomic densities. The pairing gap diminishes if two species have different densities and vanishes when the density imbalance reaches a critical value.