Charge Pumping of Interacting Fermion Atoms in the Synthetic Dimension

TL;DR

This paper explores how interactions in a synthetic dimension system of fermion atoms lead to fractional quantum Hall-like charge pumping and Mott insulator behavior, with potential experimental signatures.

Contribution

It proposes experimental signatures of interaction effects in charge pumping for fermions in synthetic dimensions, highlighting fractional quantum Hall and Mott insulator phases.

Findings

Charge pumping approaches a fractional value in strongly interacting regimes.

Charge pumping is zero at commensurate fillings, indicating Mott insulator phases.

Charge-density-wave order is discussed as part of the system's behavior.

Abstract

Recently it has been proposed and experimentally demonstrated that a spin-orbit coupled multi-component gas in 1d lattice can be viewed as spinless gas in a synthetic 2d lattice with a magnetic flux. In this letter we consider interaction effect of such a Fermi gas, and propose signatures in charge pumping experiment, which can be easily realized in this setting. Using 1/3 filling of the lowest 2d band as an example, in strongly interacting regime, we show that the charge pumping value gradually approaches a universal fractional value for large spin component and low filling of 1d lattice, indicating a fractional quantum Hall type behavior; while the charge pumping value is zero if the 1d lattice filling is commensurate, indicating a Mott insulator behavior. The charge-density-wave order is also discussed.