Floquet engineering of lattice structure and dimensionality in twisted moir\'e heterobilayers

TL;DR

This paper proposes using Floquet engineering with light to dynamically alter the lattice structure and dimensionality of twisted TMD heterobilayers, enabling exploration of novel correlated phases.

Contribution

It introduces a method to control lattice geometry and dimensionality in twisted TMDs via Floquet drive, expanding possibilities for studying correlated quantum phases.

Findings

Elliptically polarized light can switch lattice from triangular to square.

Linearly polarized light reduces system to a quasi-1D geometry.

The single band Fermi-Hubbard model remains valid under Floquet drive.

Abstract

We present an experimental proposal to tune the effective lattice structure in twisted transition metal dichalcogenide (TMD) heterobilayers with time-periodic Floquet drive. We show that elliptically polarized light with sub-terahertz frequencies $\hbar\omega\sim 1$ meV and moderate electric fields $E\sim0.2$~MV/cm allows tuning between the native triangular lattice and a square lattice, while linearly polarized light enables dimensional reduction to a quasi-one-dimensional geometry. Without drive, these twisted TMDs simulate the single band Fermi-Hubbard model; we show that this approximation still holds in the presence of drive. This control opens the door to explore a rich variety of correlated phases of matter, such as spin liquids and d-wave superconductivity.