Quantum Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates

TL;DR

This paper investigates the quantum Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates, revealing unique interface deformations and vortex formations distinct from classical fluid behavior.

Contribution

It introduces a theoretical analysis of quantum interface instability using Gross-Pitaevskii and Bogoliubov-de Gennes models, highlighting novel vortex dynamics.

Findings

Interface deforms into sawtooth or Stokes-like waves

Formation of singly quantized vortices on wave peaks and troughs

Distinct behavior from classical Kelvin-Helmholtz instability

Abstract

We theoretically study the Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates using the Gross-Pitaevskii and Bogoliubov-de Gennes models. A flat interface between the two condensates is shown to deform into sawtooth or Stokes-like waves, leading to the formation of singly quantized vortices on the peaks and troughs of the waves. This scenario of interface instability in quantum fluids is quite different from that in classical fluids.