Enhancement of chiral edge currents in ($d$+1)-dimensional atomic Mott-band hybrid insulators

TL;DR

This paper investigates how local interatomic repulsion enhances chiral edge currents in synthetic dimensions of atomic Mott insulators, revealing their persistence and maximum at the Mott transition.

Contribution

It demonstrates that chiral edge currents increase with interaction strength and reach their maximum at the Mott transition in synthetic heterostructures.

Findings

Chiral currents increase with interaction strength.

Currents reach maximum at the Mott transition.

Currents remain finite in the insulating state.

Abstract

We consider the effect of a local interatomic repulsion on synthetic heterostructures where a discrete synthetic dimension is created by Raman processes on top of $SU(N)$-symmetric two-dimensional lattice systems. At a filling of one fermion per site, increasing the interaction strength, the system is driven towards a Mott state which is adiabatically connected to a band insulator. The chiral currents associated with the synthetic magnetic field increase all the way to the Mott transition, where they reach the maximum value, and they remain finite in the whole insulating state. The transition towards the Mott-band insulator is associated with the opening of a gap within the low-energy quasiparticle peak, while a mean-field picture is recovered deep in the insulating state.