Multidimensional hybrid Bose-Einstein condensates stabilized by lower-dimensional spin-orbit coupling

TL;DR

This paper demonstrates that lower-dimensional spin-orbit coupling can stabilize multidimensional Bose-Einstein condensates in free space, revealing new hybrid states and bifurcation phenomena with potential experimental implications.

Contribution

It introduces the concept that lower-dimensional SOC can stabilize 2D and 3D BECs, and analytically describes the bifurcation of solitons near critical points.

Findings

2D states stabilized by 1D SOC over a broad chemical potential range

Striped 3D solitary states stabilized by 2D SOC in limited conditions

Identification of a boundary between single-peaked and hybrid states

Abstract

We show that attractive spinor Bose-Einstein condensates under the action of spin-orbit coupling (SOC) and Zeeman splitting form self-sustained stable two- and three-dimensional (2D and 3D) states in free space, even when SOC acts in a lower-dimensional form. We find that two-dimensional states are stabilized by one-dimensional (1D) SOC in a broad range of chemical potentials, for atom numbers (or norm of the spinor wavefunction) exceeding a threshold value, which strongly depends on the SOC strength and vanishes at a critical point. The zero-threshold point is a boundary between single-peaked and striped states, realizing hybrids combining 2D and 1D structural features. In a vicinity of such point, an asymptotic equation describing the bifurcation of the solitons from the linear spectrum is derived and investigated analytically. We show that striped 3D solitary states are as well stabilized by 2D SOC, albeit in a limited range of chemical potentials and norms.