Dynamic twisting and imaging of moir\'e crystals

TL;DR

This paper introduces a novel scanning-probe-based method for in situ, continuous twist control of moiré superlattices in 2D materials, enabling detailed exploration of angle-dependent quantum phenomena.

Contribution

It presents a new in situ twist control technique using nanostructured metal rotors, allowing precise, reproducible angle tuning and imaging in various 2D material platforms.

Findings

Achieved sub-degree twist angle precision with minimal heterostrain.

Demonstrated continuous angle tuning and imaging in graphene, hBN, and MoTe2.

Maintained open access for optical, scanning-probe, and transport measurements.

Abstract

Moir\'e superlattices in stacked 2D crystals are powerful platforms for engineering correlated and topological quantum phases, with twisted graphene and transition metal dichalcogenides (TMDs) as prominent examples. Their angle-sensitive band structures enable rich tunability; however, conventional tear-and-stack methods fix the angle at assembly, limiting systematic exploration of angle-dependent phenomena. Here, we present a scanning-probe-based manipulation scheme that enables in situ, continuous post-fabrication twist control using nanostructured metal rotors. We demonstrate reproducible angle tuning and direct moir\'e imaging across three platforms: graphene, hBN, and encapsulated, air-sensitive MoTe2. Quantitative piezoresponse force microscopy (PFM) analysis confirms sub-degree precision with minimal induced heterostrain, preserving sample quality even in the marginally twisted regime. Crucially, the device architecture maintains open access to the active region, allowing optical, scanning-probe, and transport measurements. This work enables single-device mapping of the angular phase diagram of moir\'e materials, including the twisted TMD homobilayers.