Engineering band structures of two-dimensional materials with remote moire ferroelectricity

TL;DR

This paper demonstrates how remote moire ferroelectricity in twisted bilayer WSe2 can engineer band structures in adjacent graphene layers, enabling tunable electronic properties through long-range electrostatic potentials.

Contribution

It introduces a novel approach to engineer 2D material band structures using remote moire ferroelectricity, separating the moire layer from the electronic transport layer.

Findings

Remote moire potential induces satellite resistance peaks in graphene.

Ferroelectric hysteresis observed at finite displacement fields.

Twist angle controls the strength of the moire potential.

Abstract

The stacking order and twist angle provide abundant opportunities for engineering band structures of two-dimensional materials, including the formation of moire bands, flat bands, and topologically nontrivial bands. The inversion symmetry breaking in rhombohedral-stacked transitional metal dichalcogenides (TMDCs) endows them with an interfacial ferroelectricity associated with an out-of-plane electric polarization. By utilizing twist angle as a knob to construct rhombohedral-stacked TMDCs, antiferroelectric domain networks with alternating out-of-plane polarization can be generated. Here, we demonstrate that such spatially periodic ferroelectric polarizations in parallel-stacked twisted WSe2 can imprint their moire potential onto a remote bilayer graphene. This remote moire potential gives rise to pronounced satellite resistance peaks besides the charge-neutrality point in graphene, which are tunable by the twist angle of WSe2. Our observations of ferroelectric hysteresis at finite displacement fields suggest the moire is delivered by a long-range electrostatic potential. The constructed superlattices by moire ferroelectricity represent a highly flexible approach, as they involve the separation of the moire construction layer from the electronic transport layer. This remote moire is identified as a weak potential and can coexist with conventional moire. Our results offer a comprehensive strategy for engineering band structures and properties of two-dimensional materials by utilizing moire ferroelectricity.