Robustness of Fractional Quantum Hall States with Dipolar Atoms in Artificial Gauge Fields

TL;DR

This paper investigates the energy gap and robustness of fractional quantum Hall states in dipolar atomic systems under artificial gauge fields, revealing that non-Abelian fields significantly enhance the gap compared to Abelian fields.

Contribution

The study introduces a thermodynamic approximation method to evaluate the energy gap and demonstrates the impact of non-Abelian gauge fields in increasing the stability of fractional quantum Hall states.

Findings

The energy gap in Abelian gauge fields is smaller than previously predicted.

Non-Abelian gauge fields dramatically increase the energy gap.

Results align with exact diagonalization for small systems.

Abstract

The robustness of fractional quantum Hall states is measured as the energy gap separating the Laughlin ground-state from excitations. Using thermodynamic approximations for the correlation functions of the Laughlin state and the quasihole state, we evaluate the gap in a two-dimensional system of dipolar atoms exposed to an artificial gauge field. For Abelian fields, our results agree well with the results of exact diagonalization for small systems, but indicate that the large value of the gap predicted in [Phys. Rev. Lett. 94, 070404 (2005)] was overestimated. However, we are able to show that the small gap found in the Abelian scenario is dramatically increased if we turn to non-Abelian fields squeezing the Landau levels.