Ground-state multiquantum vortices in rotating two-species superfluids

TL;DR

This paper demonstrates through numerical simulations that a two-species Bose-Einstein condensate can host stable, multiply quantized vortices in its ground state, revealing new exotic physics in multi-component superfluids.

Contribution

It introduces the first numerical evidence of stable, multiquantum vortices in the ground state of a two-species superfluid system, expanding understanding of vortex phenomena.

Findings

Stable, multiply quantized vortices can exist in the ground state.

Such vortices can be coreless or have an empty core.

The phenomenon is demonstrated in a $^{87}$Rb-$^{41}$K BEC.

Abstract

We show numerically that a rotating, harmonically trapped mixture of two Bose-Einstein-condensed superfluids can, contrary to its single-species counterpart, contain a multiply quantized vortex in the ground state of the system. This giant vortex can occur without any accompanying single-quantum vortices, may either be coreless or have an empty core, and can be realized in a $^{87}$Rb-$^{41}$K Bose-Einstein condensate. Our results not only provide a rare example of a stable, solitary multiquantum vortex but also reveal exotic physics stemming from the coexistence of multiple, compositionally distinct condensates in one system.