Formation of Feshbach molecules in the presence of artificial spin-orbit coupling and Zeeman fields

TL;DR

This paper derives conditions for forming Feshbach molecules in ultra-cold fermionic gases with artificial spin-orbit coupling and Zeeman fields, analyzing how these factors influence bound state energies.

Contribution

It provides a general theoretical framework for understanding Feshbach molecule formation under complex spin-orbit and Zeeman interactions in cold atom systems.

Findings

Explicit binding energy calculations for Feshbach molecules.

Dependence of binding energies on spin-orbit coupling and Zeeman fields.

Special focus on equal Rashba and Dresselhaus couplings.

Abstract

We derive general conditions for the emergence of singlet Feshbach molecules in the presence of artificial Zeeman fields for arbritary mixtures of Rashba and Dresselhaus spin-orbit orbit coupling in two or three dimensions. We focus on the formation of two-particle bound states resulting from interactions between ultra-cold spin-1/2 fermions, under the assumption that interactions are short-ranged and occur only in the s-wave channel. In this case, we calculate explicitly binding energies of Feshbach molecules and analyze their dependence on spin-orbit couplings, Zeeman fields, interactions and center of mass momentum, paying particular attention to the experimentally relevant case of spin-orbit couplings with equal Rashba and Dresselhaus (ERD) amplitudes.