# Quantum solitons in spin-orbit-coupled Bose-Bose mixtures

## TL;DR

This paper investigates quantum solitons in one-dimensional spin-orbit-coupled Bose-Bose mixtures, revealing how quantum fluctuations and couplings produce stable self-bound states and phase transitions.

## Contribution

It introduces a detailed phase diagram for soliton states considering spin-orbit and Rabi couplings, highlighting the role of quantum fluctuations in stabilization.

## Key findings

- Existence of quantum fluctuation-driven bright solitons.
- Phase transition between single-peak and multipeak solitons.
- Self-confined propagating solitary waves via phase imprinting.

## Abstract

Recent experimental and theoretical results show that weakly interacting atomic Bose-Bose mixtures with attractive interspecies interaction are stabilized by beyond-mean-field effects. Here we consider the peculiar properties of these systems in a strictly one-dimensional configuration, taking also into account the nontrivial role of spin-orbit and Rabi couplings. We show that when the value of inter- and intraspecies interaction strengths are such that mean-field contributions to the energy cancel, a self-bound bright soliton fully governed by quantum fluctuations exists. We derive the phase diagram of the phase transition between a single-peak soliton and a multipeak (striped) soliton, produced by the interplay between spin-orbit, Rabi couplings and beyond-mean-field effects, which also affect the breathing mode frequency of the atomic cloud. Finally, we prove that a phase imprinting of the single-peak soliton leads to a self-confined propagating solitary wave even in the presence of spin-orbit coupling.