Transport measurements on van der Waals heterostructures under pressure

TL;DR

This paper introduces a new method to apply hydrostatic pressure to van der Waals heterostructure nanocircuits, enabling transport measurements under pressure and revealing pressure effects on interlayer coupling.

Contribution

A novel technique for tuning interlayer coupling in van der Waals heterostructures using hydrostatic pressure with a specialized pressure cell and sample holder.

Findings

Hexagonal boron nitride protects heterostructures under pressure.

Pressure influences interlayer coupling as shown by weak localization.

Method allows transport measurements with up to 12 contacts under pressure.

Abstract

The interlayer coupling, which has a strong influence on the properties of van der Waals heterostructures, strongly depends on the interlayer distance. Although considerable theoretical interest has been demonstrated, experiments exploiting a variable interlayer coupling on nanocircuits are scarce due to the experimental difficulties. Here, we demonstrate a novel method to tune the interlayer coupling using hydrostatic pressure by incorporating van der Waals heterostructure based nanocircuits in piston-cylinder hydrostatic pressure cells with a dedicated sample holder design. This technique opens the way to conduct transport measurements on nanodevices under pressure using up to 12 contacts without constraints on the sample at fabrication level. Using transport measurements, we demonstrate that hexagonal boron nitride capping layer provides a good protection of van der Waals heterostructures from the influence of the pressure medium, and we show experimental evidence of the influence of pressure on the interlayer coupling using weak localization measurements on a TMDC/graphene heterostructure.