One- and two-dimensional solitons in spin-orbit-coupled Bose-Einstein condensates with fractional kinetic energy

TL;DR

This paper investigates how spin-orbit coupling influences the formation and stability of one- and two-dimensional solitons in fractional kinetic energy Bose-Einstein condensates, revealing new stable soliton families in specific parameter regimes.

Contribution

It introduces a model combining fractional kinetic energy and SOC in BECs, demonstrating the existence of stable semi-vortex and mixed-mode solitons for fractional Levy indices between 1 and 2.

Findings

Stable semi-vortex and mixed-mode solitons exist for 1<α<2 with SOC.

Soliton amplitudes scale as λ^{1/(α-1)} when SOC strength λ approaches zero.

SOC induces strong effects and stabilizes solitons in regimes where they would otherwise collapse.

Abstract

We address effects of spin-orbit coupling (SOC), phenomenologically added to a two-component Bose-Einstein condensate composed of particles moving by Levy flights, in one- and two-dimensional (1D and 2D) settings. The corresponding system of coupled Gross-Pitaevskii equations includes fractional kinetic-energy operators, characterized by the Levy index, \alpha < 2 (the normal kinetic energy corresponds to \alpha = 2). The SOC terms, with strength \lambda, produce strong effects in the 2D case: they create families of stable solitons of the semi-vortex (SV) and mixed-mode (MM) types in the interval of 1 < \alpha < 2, where the supercritical collapse does not admit the existence of stable solitons in the absence of the SOC. At \lambda --> 0, amplitudes of these solitons vanish as (\lambda)^{1/(\alpha - 1)}.