Visualization of vortex bound states in polarized Fermi gases at unitarity

TL;DR

This paper theoretically investigates vortex bound states in polarized 3D Fermi gases near unitarity, revealing how polarization affects core density and bound state energies, enabling visualization via absorption imaging.

Contribution

It provides a detailed analysis of vortex core states in polarized Fermi gases at unitarity, highlighting the impact of polarization on bound state occupation and core expansion.

Findings

Occupation of bound states increases with polarization

Core density difference exhibits a sudden rise at low temperatures

Bound state energy decreases as polarization increases

Abstract

We analyse theoretically a single vortex in 3D trapped atomic Fermi gases with population polarization near a broad Feshbach resonance. Above a critical polarization the Andreev-like bound states inside the core become occupied for the majority component. As a result, the local density difference at the core center acquires a sudden rise at low temperautres. This provides a visualization of the lowest bound state within the absorption imaging technique. As the polarization increases, the core expands gradually, and correspondingly, the energy of the lowest bound state decreases.