Bose-Fermi Mixtures in Optical Lattices

TL;DR

This paper investigates how optical lattices influence the stability and vortex formation in Bose-Fermi mixtures with attractive interactions, revealing that deeper lattices lower the critical frequency for vortices and induce earlier instability.

Contribution

It provides a mean field theoretical analysis of the effects of optical lattice depth on vortex nucleation and stability in Bose-Fermi mixtures with attractive interactions.

Findings

Deeper optical lattices reduce the critical rotational frequency for vortex creation.

Optimal stability of the mixture decreases with increasing lattice depth.

Instability occurs at lower fermion numbers in deeper lattices.

Abstract

Using mean field theory, we have studied Bose-Fermi mixtures in a one-dimensional optical lattice in the case of an attractive boson-fermion interaction. We consider that the fermions are in the degenerate regime and that the laser intensities are such that quantum coherence across the condensate is ensured. We discuss the effect of the optical lattice on the critical rotational frequency for vortex line creation in the Bose-Einstein condensate, as well as how it affects the stability of the boson-fermion mixture. A reduction of the critical frequency for nucleating a vortex is observed as the strength of the applied laser is increased. The onset of instability of the mixture occurs for a sizeably lower number of fermions in the presence of a deep optical lattice.