Fragmentation of Spin-orbit Coupled Spinor Bose-Einstein Condensates

TL;DR

This paper investigates how spin-orbit coupling and interactions influence the fragmentation and angular momentum properties of spinor Bose-Einstein condensates using both exact and mean-field methods.

Contribution

It provides a detailed analysis of the effects of spin-orbit coupling and interaction types on fragmentation and angular momentum in spinor BECs, highlighting the role of these factors in ground state selection.

Findings

Stronger spin-orbit coupling increases the inverse participation ratio.

Changing interaction from anti-ferromagnetic to ferromagnetic lowers the inverse participation ratio peaks.

The condensate's total angular momentum ground state depends on interaction and spin-orbit strength.

Abstract

The fragmentation of spin-orbit coupled spin-1 Bose gas with a weak interaction in external harmonic trap is explored by both exact diagonalization and mean-field theory. This fragmentation tendency, which originates from the total angular momentum conservation, is affected obviously by the spin-orbit coupling strength and the spin-dependent interaction. Strong spin-orbit interaction raises the inverse participation ratio, which describes the number of significantly occupied single-particle states. As the spin-dependent interaction changes from anti-ferromagnetic to ferromagnetic, the peak values in the inverse participation ratio become lower. Without the confinement of the appointed total angular momentum, the condensate chooses a zero or finite total angular momentum ground state, which is determined by both the interaction and the spin-orbit coupling strength.