Singlet and triplet BCS pairs in a gas of two-species fermionic polar molecules

TL;DR

This paper explores BCS pairing mechanisms in a two-species fermionic polar molecule gas, revealing the coexistence of singlet and triplet pairs, and demonstrates how tuning interactions can switch between these pairing states.

Contribution

It derives coupled gap equations for singlet and triplet pairing and shows how to control the pairing state via short-range interaction tuning.

Findings

Supports both singlet and triplet BCS pairs

Calculates critical temperatures and order parameter angular dependence

Shows transition control between pairing states through interaction tuning

Abstract

We investigate the BCS pairing in a mixture of fermionic polar molecules with two different hyperfine states. We derive a set of coupled gap equations and find that this system supports both spin-singlet and -triplet BCS pairs. We also calculate the critical temperatures and the angular dependence of order parameters. In addition, by tuning short-range interaction between inter-species molecules, the transition between singlet and triplet paired states may be realized.