Constructing a Quantum Twisting Microscope: Design Insights and Experimental Considerations

TL;DR

This paper details the design, construction, and testing of a Quantum Twisting Microscope, enabling precise twist angle measurements in layered materials using a modified atomic force microscope.

Contribution

It introduces a comprehensive fabrication and alignment process for a Quantum Twisting Microscope compatible with standard AFMs, facilitating twist angle dependent studies.

Findings

Confirmed the instrument's ability to measure conductance variations with twist angle.

Observed 60-degree periodicity consistent with lattice symmetry.

Detected conductance enhancements at specific commensurate angles.

Abstract

We report the details of construction and testing of a Quantum Twisting Microscope, a recently developed scanning probe instrument that enables twist angle dependent electronic measurements on layered materials. Our implementation is based on a commercial atomic force microscope whose open geometry beneath the scan head allows integration of the rotation and translation stages required for QTM operation. We describe the complete fabrication process including tip preparation by focused ion beam deposition and graphite transfer, custom stage assembly with integrated rotation capability, and multistep alignment procedures. To validate the instrument, we perform conductance measurements between graphite layers as a function of twist angle, observing clear 60 degree periodicity consistent with the hexagonal lattice symmetry and conductance enhancements near the commensurate twist angles of 21.8 and 38.2 degrees. These results confirm the instruments ability to resolve crystallographic twist angle dependent transport features. By providing detailed construction and operational guidelines, we aim to make QTM technology accessible to research groups with standard AFM infrastructure, enabling investigations of twist angle dependent phenomena in van der Waals materials, complex oxide heterostructures and chiral systems.