Matter-wave bright solitons in spin-orbit coupled Bose-Einstein condensates

TL;DR

This paper investigates matter-wave bright solitons in spin-orbit coupled Bose-Einstein condensates with attractive interactions, identifying different soliton types and analyzing their stability through analytical and numerical methods.

Contribution

It introduces a multiscale expansion approach to find soliton solutions in SO-coupled BECs and explores their properties depending on system parameters.

Findings

Solitons can resemble standard bright solitons or exhibit stripe-like modulations.

Analytical solutions agree well with numerical simulations.

Solitons show potential robustness under experimental conditions.

Abstract

We study matter-wave bright solitons in spin-orbit (SO) coupled Bose-Einstein condensates (BECs) with attractive interatomic interactions. We use a multiscale expansion method to identify solution families for chemical potentials in the semi-infinite gap of the linear energy spectrum. Depending on the linear and spin-orbit coupling strengths, the solitons may resemble either standard bright nonlinear Schr\"{o}dinger solitons or exhibit a modulated density profile, reminiscent of the stripe phase of SO-coupled repulsive BECs. Our numerical results are in excellent agreement with our analytical findings, and demonstrate the potential robustness of such solitons for experimentally relevant conditions through stability analysis and direct numerical simulations.