Quantum Hall States in Rapidly Rotating Two-Component Bose Gases

TL;DR

This paper explores the emergence of non-Abelian spin-singlet states in rapidly rotating two-component Bose gases, revealing phase transitions influenced by interaction ratios through exact diagonalization methods.

Contribution

It demonstrates the formation of gapped spin-singlet states at specific filling factors and identifies a phase transition to non-Abelian states driven by interaction ratios.

Findings

Identification of gapped spin-singlet states at filling factors rac{k}{3}+rac{k}{3}

Numerical evidence for a non-Abelian spin-singlet state at k=2

Observation of phase transition influenced by intercomponent to intracomponent interaction ratio

Abstract

We investigate strongly correlated phases of two-component (or pseudo-spin-1/2) Bose gases under rapid rotation through exact diagonalization on a torus geometry. In the case of pseudo-spin-independent contact interactions, we find the formation of gapped spin-singlet states at the filling factors \nu=k/3+k/3 (k/3 filling for each component) with integer k. We present numerical evidences that the gapped state with k=2 is well described as a non-Abelian spin-singlet (NASS) state, in which excitations feature non-Abelian statistics. Furthermore, we find the phase transition from the product of composite fermion states to the NASS state by changing the ratio of the intercomponent to intracomponent interactions.