Interaction enhanced inter-site hoppings for holons and interlayer exciton insulators in moir\'e correlated insulators

TL;DR

This paper theoretically studies how Coulomb interactions enhance inter-site hoppings of holons and interlayer exciton insulators in moiré TMD structures, revealing mechanisms for correlated insulating states.

Contribution

It introduces a theoretical analysis showing significant enhancement of inter-site hoppings due to Coulomb interactions in moiré TMDs, including effective parameters for interlayer exciton insulators.

Findings

Hopping strengths are significantly enhanced compared to single carriers.

Coulomb interactions are the key mechanism for hopping enhancement.

Effective Bohr radius and energy splitting are calculated for interlayer exciton insulators.

Abstract

In moir\'e-patterned van der Waals structures of transition metal dichalcogenides, correlated insulators can form under integer and fractional fillings, whose transport properties are governed by various quasiparticle excitations including holons, doublons and interlayer exciton insulators. Here we theoretically investigate the nearest-neighbor inter-site hoppings of holons and interlayer exciton insulators. Our analysis indicates that these hopping strengths are significantly enhanced compared to that of a single carrier. The underlying mechanism can be attributed to the strong Coulomb interaction between carriers at different sites. For the interlayer exciton insulator consisting of a holon and a carrier in different layers, we have also obtained its effective Bohr radius and energy splitting between the ground and first-excited states.