Moir\'e straintronics: a universal platform for reconfigurable quantum materials

TL;DR

This paper introduces strain as a versatile tool to precisely control the periodicity and symmetry of moiré superlattices in 2D materials, enabling new ways to engineer and study strongly correlated quantum phases.

Contribution

It develops an exact mathematical framework for moiré lattices under arbitrary in-plane heterostrain, expanding the tuning capabilities beyond twist angle control.

Findings

Strain can reconfigure moiré lattice symmetry beyond unstrained crystals.

Precise control of moiré periodicity near critical points like the magic angle.

Strain enables tuning of electronic interactions in 2D heterostructures.

Abstract

Large scale two-dimensional (2D) moir\'e superlattices are driving a revolution in designer quantum materials. The electronic interactions in these superlattices, strongly dependent on the periodicity and symmetry of the moir\'e pattern, critically determine the emergent properties and phase diagrams. To date, the relative twist angle between two layers has been the primary tuning parameter for a given choice of constituent crystals. Here, we establish strain as a powerful mechanism to in-situ modify the moir\'e periodicity and symmetry. We develop an analytically exact mathematical description for the moir\'e lattice under arbitrary in-plane heterostrain acting on any bilayer structure. We demonstrate the ability to fine-tune the moir\'e lattice near critical points, such as the magic angle in bilayer graphene, or fully reconfigure the moir\'e lattice symmetry beyond that imposed by the unstrained constituent crystals. Due to this unprecedented simultaneous control over the strength of electronic interactions and lattice symmetry, 2D heterostrain provides a powerful platform to engineer, tune, and probe strongly correlated moir\'e materials.