Quantum Hall Transition near a Fermion Feshbach Resonance in a Rotating Trap

TL;DR

This paper studies a quantum phase transition in a rotating two-species fermionic system near a Feshbach resonance, revealing a transition from an integer to a fractional quantum Hall state driven by pairing interactions.

Contribution

It introduces an effective field theory describing the transition as a massless relativistic bosonic field coupled to a Chern-Simons gauge field, highlighting emergent semionic statistics.

Findings

Transition occurs near the Feshbach resonance as pairing strength increases.

The effective theory involves a massless bosonic field coupled to a Chern-Simons gauge field.

Emergent particles exhibit semionic statistics.

Abstract

We consider two-species of fermions in a rotating trap that interact via an s-wave Feshbach resonance, at total Landau level filling factor two (or one for each species). We show that the system undergoes a quantum phase transition from a fermion integer quantum Hall state to a boson fractional quantum Hall state as the pairing interaction strength increases, with the transition occurring near the resonance. The effective field theory for the transition is shown to be that of a (emergent) massless relativistic bosonic field coupled to a Chern-Simons gauge field, with the coupling giving rise to semionic statistics to the emergent particles.