Mechanically-reconfigurable van der Waals devices via low-friction gold sliding

TL;DR

This paper demonstrates low-friction gold sliding on hBN, enabling the creation of mechanically reconfigurable van der Waals devices with tunable geometry and position, facilitating novel in-situ electronic and scanning probe experiments.

Contribution

It introduces a method for low-friction gold sliding on hBN, allowing post-fabrication reconfiguration of vdW devices and enabling new experimental capabilities.

Findings

Gold slides with low friction on hBN.

Reconfigurable quantum point contacts with tunable electron confinement.

In-situ sliding combined with electronic measurements for scanning probe applications.

Abstract

Interfaces of van der Waals (vdW) materials such as graphite and hexagonal boron nitride (hBN) exhibit low-friction sliding due to their atomically-flat surfaces and weak vdW bonding. We demonstrate that microfabricated gold also slides with low friction on hBN. This enables the arbitrary post-fabrication repositioning of device features both at ambient conditions as well as in-situ to a measurement cryostat. We demonstrate mechanically-reconfigurable vdW devices where device geometry and position are continuously-tunable parameters. By fabricating slidable top gates on a graphene-hBN device, we produce a mechanically-tunable quantum point contact where electron confinement and edge-state coupling can be continuously modified. Moreover, we combine in-situ sliding with simultaneous electronic measurements to create new types of scanning probe experiments, where gate electrodes and even entire vdW heterostructures devices can be spatially scanned by sliding across a target.