Angular spin-orbit coupling in cold atoms

TL;DR

This paper introduces a novel method to induce angular spin-orbit coupling in cold atoms using Laguerre-Gaussian Raman beams, analyzing its effects on single-particle states and weakly interacting condensates.

Contribution

It presents a new scheme for angular spin-orbit coupling in cold atoms and explores its impact on atomic ground states and interactions.

Findings

Realistic parameters enable effective angular spin-orbit coupling.

Spin textures of the ground state are characterized.

Interactions modify single-particle physics significantly.

Abstract

We propose coupling two internal atomic states using a pair of Raman beams operated in Laguerre-Gaussian laser modes with unequal phase windings. This generates a coupling between the atom's pseudo-spin and its orbital angular momentum. We analyze the single-particle properties of the system using realistic parameters and provide detailed studies of the spin texture of the ground state. Finally, we consider a weakly interacting atomic condensate subject to this angular spin-orbit coupling and show how the inter-atomic interactions modifies the single-particle physics.