Split-gate point-contact for channelizing electron transport on MoS2/h-BN hybrid structures

TL;DR

This paper demonstrates a split-gate point contact device on MoS2/h-BN heterostructures, enabling electrostatically controlled electron transport, a key step towards quantum circuits on 2D materials, with tunable pinch-off behavior across a wide temperature range.

Contribution

It introduces the first split-gate point contact device on MoS2/h-BN heterostructures, showing channelization and tunability of electron flow in 2D semiconductor heterostructures.

Findings

Device exhibits channelized electron flow and pinch-off behavior.

Pinch-off characteristics can be tuned by back-gate voltage.

Operation is effective from 4K to 300K.

Abstract

Electrostatically defined nanoscale devices on two-dimensional semiconductor heterostructures are the building blocks of various quantum electrical circuits. Owing to its atomically flat interfaces and the inherent two-dimensional nature, van der Waals heterostructures hold the advantage of large-scale uniformity, flexibility and portability over the conventional bulk semiconductor heterostructures. In this letter we show the operation of a split-gate defined point contact device on a MoS2/h-BN heterostructure, a first step towards realizing electrostatically gated quantum circuits on van der Waals semiconductors. Our devices show signatures of channelized electron flow and a complete shutdown of transport similar to the conventional point contacts defined on bulk semiconductor heterostructures. We explore the role of back-gate and the drain-source voltages on the pinch-off characteristics and, we are able to tune the pinch-off characteristics by varying the back-gate voltage at temperatures ranging from 4K to 300 K.