Formation of quantum dots in MoS2 with cryogenic Bi contacts and intrinsic Schottky barriers

TL;DR

This paper demonstrates the formation of quantum dots in multilayer MoS2 using cryogenic Bi contacts and intrinsic Schottky barriers, enabling quantum transport studies at very low temperatures.

Contribution

It introduces a novel fabrication method employing Bi contacts and Schottky barriers in MoS2 devices for quantum dot formation and quantum transport analysis.

Findings

Observed Ohmic behavior in MoS2-Bi devices at cryogenic temperatures.

Detected Coulomb diamonds indicating quantum dot formation.

Potential for exploring spin-valley coupling and qubit manipulation.

Abstract

The recent advancement in two-dimensional (2D) materials-based quantum confinement has provided an opportunity to investigate and manipulate electron transport for quantum applications. However, the issues of metal/semiconductor interface effects create a hurdle to realize the artificial fabrication of the quantum dot and study the quantum transport. Here, we utilize the strategy of employing the semimetal for Ohmic contacts with transition metal dichalcogenides especially, multilayer MoS2 and successfully fabricate the MoS2-Bi based FET devices. We observe the Ohmic behavior in the MoS2-Bi devices at cryogenic temperatures 4.2, 2.3 and 0.4 K. We also utilize intrinsic Schottky barriers formed at the interface between MoS2 and Au for the gate electrodes to form and control quantum dots. We observed Coulomb diamonds in MoS2 devices at cryogenic temperature. Our results of quantum transport in MoS2 could serve as a stepping stone for investigating novel quantum effects such as spin-valley coupling and the manipulation of qubit systems.