Vortex Synchronization in Bose-Einstein Condensates: A Time-Dependent Gross-Pitaevskii Equation Approach

TL;DR

This paper investigates vortex lattice locking in rotating two-species Bose-Einstein Condensates with different masses, using numerical solutions of the two-component Gross-Pitaevskii equations to verify the stability and extent of vortex locking.

Contribution

It provides the first numerical verification of vortex locking stability in two-species BECs with mass disparity, and compares it with an analytic force-based estimate.

Findings

Vortex locking occurs within a specific radius dependent on mass ratio.

Numerical results confirm the stability of the locked vortex state.

Analytic estimates match well with numerical simulations.

Abstract

In this work we consider vortex lattices in rotating Bose-Einstein Condensates composed of two species of bosons having different masses. Previously [1] it was claimed that the vortices of the two species form bound pairs and the two vortex lattices lock. Remarkably, the two condensates and the external drive all rotate at different speeds due to the disparity of the masses of the constituent bosons. In this paper we study the system by solving the full two-component Gross-Pitaevskii equations numerically. Using this approach we verify the stability of the putative locked state which is found to exist within a disk centered on the axis of rotation and which depends on the mass ratio of the two bosons. We also show that an analytic estimate of this locking radius based on a two-body force calculation agrees well with the numerical results.