Dynamics of vortex matter in rotating two-species Bose-Einstein condensates

TL;DR

This paper investigates the complex vortex structures and excitations in rotating two-species Bose-Einstein condensates, revealing new phenomena like shear flow between vortex sheets through analysis of the Bogoliubov spectrum.

Contribution

It introduces a detailed analysis of vortex lattice dynamics in two-component BECs, highlighting the emergence of novel phenomena due to interspecies interactions.

Findings

Transition from triangular to rectangular vortex lattices

Identification of shear flow between vortex sheets

Presence of Tkachenko, hydrodynamic, and surface wave modes

Abstract

In a rotating two-component Bose-Einstein condensate (BEC), the traditional triangular vortex lattice can be replaced by a rectangular vortex lattice or even a structure characterized in terms of vortex sheets, depending on the interspecies interactions. We study the dynamics of this system by analyzing the Bogoliubov excitation spectrum. Excitations familiar to BEC vortex systems are found such as Tkachenko modes, hydrodynamic modes and surface waves, however, the complex two-component morphology also gives rise to new phenomena including shear flow between vortex sheets.