Bosonic Halperin fractional quantum Hall effect at filling factor $\nu=2/5$

TL;DR

This paper investigates the emergence of two competing fractional quantum Hall states in a two-component bosonic system at filling factor 2/5, revealing their topological properties and phase transition scenarios.

Contribution

It demonstrates, through numerical methods, the existence of two distinct Halperin fractional quantum Hall states in bosonic systems and analyzes their topological features and phase transitions.

Findings

Identification of Halperin (441) and (223) FQH states in bosonic systems

Topological characterization including ground state degeneracy and Chern number matrix

Analysis of phase transition driven by intercomponent coupling strength

Abstract

Quantum Hall effects with multicomponent internal degrees of freedom facilitate the playground of novel emergent topological orders. Here, we explore the correlated topological phases of two-component hardcore bosons at a total filling factor $\nu=2/5$ in both lattice Chern band models and Landau level continuum model under the interplay of intracomponent and intercomponent repulsions. We give the numerically theoretical demonstration of the emergence of two competing distinct fractional quantum Hall states: Halperin (441) fractional quantum Hall effect and Halperin (223) fractional quantum Hall effect. We elucidate their topological features including the degeneracy of the ground state and fractionally quantized topological Chern number matrix. Finally, we discuss scenarios related to phase transition between them when intercomponent nearest-neighbor coupling is tuned from weak to strong in topological checkerboard lattice.