Continuous phase transitions between fractional quantum Hall states and symmetry-protected topological states

TL;DR

This paper investigates quantum phase transitions in Bose-Fermi mixtures under quantum Hall conditions, revealing a continuous transition from fractional quantum Hall states to symmetry-protected topological states driven by interspecies interactions.

Contribution

It introduces a new SPT state in Bose-Fermi mixtures and provides numerical evidence for a continuous phase transition between FQH and SPT states, described by Chern-Simons-Higgs theories.

Findings

Identification of a symmetry-protected topological state as the ground state at strong interspecies interaction.

Numerical evidence of a continuous phase transition between FQH and SPT states.

Scaling behavior of entanglement entropy near the transition.

Abstract

We study quantum phase transitions in Bose-Fermi mixtures driven by interspecies interaction in the quantum Hall regime. In the absence of such an interaction, the bosons and fermions form their respective fractional quantum Hall (FQH) states at certain filling factors. A symmetry-protected topological (SPT) state is identified as the ground state for strong interspecies interaction. The phase transitions between them are proposed to be described by Chern-Simons-Higgs field theories. For a simple microscopic Hamiltonian, we present numerical evidence for the existence of the SPT state and a continuous transition to the FQH state. It is also found that the entanglement entropy between the bosons and fermions exhibits scaling behavior in the vicinity of this transition.