Low-density molecular gas of tightly-bound Rashba-Dresselhaus fermions

TL;DR

This paper provides an exact solution for two-particle pairing in spin-orbit-coupled fermions and explores observable pairing signatures in a thermal gas, advancing understanding of Rashba-Dresselhaus systems.

Contribution

It introduces a new exact solution to the two-particle pairing problem with arbitrary spin-orbit interactions and analyzes observable signatures in a thermal gas.

Findings

Exact molecular wave function and Green function derived

Pairing signatures observable in time-of-flight measurements

Spectrum and binding energy of molecular states characterized

Abstract

We study interacting Rashba-Dresselhaus fermions in two spatial dimensions. First, we present a new exact solution to the two-particle pairing problem of spin-orbit-coupled fermions for arbitrary Rashba and Dresselhaus spin-orbit interactions. An exact molecular wave function and the Green function are explicitly derived along with the binding energy and the spectrum of the molecular state. In the second part, we consider a thermal Boltzmann gas of fermionic molecules and compute the time-of-flight velocity and spin distributions for a single fermion in the gas. We show that the pairing signatures can be observed already in the first-moment expectation values, such as time-of-flight density and spin profiles.