Synthetic 3D Spin-Orbit Coupling

TL;DR

This paper introduces a method to generate three-dimensional Rashba spin-orbit coupling in ultracold atoms using laser-induced Raman transitions, resulting in robust Dirac points and bound states.

Contribution

It presents a novel laser-based technique to realize 3D spin-orbit coupling with a tetrahedral atomic state configuration in ultracold gases.

Findings

Creates a robust Dirac point in the system

Demonstrates the formation of molecular bound states

Provides an exact theoretical result for fermionic systems

Abstract

We describe a method for creating a three-dimensional analogue to Rashba spin-orbit coupling in systems of ultracold atoms. This laser induced coupling uses Raman transitions to link four internal atomic states with a tetrahedral geometry, and gives rise to a Dirac point that is robust against environmental perturbations. We present an exact result showing that such a spin-orbit coupling in a fermionic system always rise to a molecular bound state.