# Vortex-core structure in a mixture of Bose and Fermi superfluids

## TL;DR

This paper investigates how the core structure of a quantized vortex in a Bose-Fermi superfluid mixture changes with varying density ratios, revealing a transition where fermions are depleted from the vortex core, which can be experimentally observed.

## Contribution

It identifies a transition in vortex-core structure in Bose-Fermi mixtures, highlighting the depletion of fermions and localization of BEC in the vortex core as the density ratio varies.

## Key findings

- Fermion depletion in vortex core at certain density ratios
- Localization of BEC in vortex core during transition
- Vortex properties change significantly across the transition

## Abstract

We study a single quantized vortex in the fermionic component of a mixture of Fermi superfluid and Bose-Einstein condensate. As the density ratio between the boson and the fermion components is tuned, we identify a transition in the vortex-core structure, across which fermions in the vortex core become completely depleted even in the weak-coupling Bardeen-Cooper-Schrieffer regime. This is accompanied by changes in key properties of the vortex state, as well as by the localization of the Bose-Einstein condensate in the vortex core. The transition in the vortex-core structure can be experimentally probed in Bose-Fermi superfluid mixtures by detecting the size and visibility of the vortices.