Dynamics of spin-orbit coupled Bose-Einstein condensates in a random potential

TL;DR

This paper investigates how disorder affects spin dynamics in spin-orbit coupled Bose-Einstein condensates, revealing two concurrent mechanisms—precessional and anomalous—that influence spin evolution and condensate behavior.

Contribution

It identifies and characterizes two distinct mechanisms of spin evolution in disordered spin-orbit coupled BECs, highlighting their roles in condensate dynamics.

Findings

Two mechanisms of spin evolution are identified: precessional and anomalous.

Condensate expansion involves random displacement and fragmentation.

Different stages of evolution can be characterized by spin dynamics.

Abstract

Disorder plays a crucial role in spin dynamics in solids and condensed matter systems. We demonstrate that for a spin-orbit coupled Bose-Einstein condensate in a random potential two mechanisms of spin evolution, that can be characterized as "precessional" and "anomalous", are at work simultaneously. The precessional mechanism, typical for solids, is due to the condensate displacement. The unconventional "anomalous" mechanism is due to the spin-dependent velocity producing the distribution of the condensate spin polarization. The condensate expansion is accompanied by a random displacement and fragmentation, where it becomes sparse, as clearly revealed in the spin dynamics. Thus, different stages of the evolution can be characterized by looking at the condensate spin.