Solitary confinement in atomically thin semiconductors

Abstract

Electrons are often confined using electrostatically defined gates to form quantum dots (QDs). However, naturally occurring TMDCs may possess intrinsic defects that could lead to the formation of inhomogeneous disordered potential throughout the material. This may lead to less efficient electrostatic control of QDs which its success is crucial in contributing to the success of quantum computing.

In this report, we demonstrate electron confinement due to disordered potential by fabricating a MoS2 transistor with a split-gate structure through mechanical exfoliation, electron-beam lithography and stacking methods. Thereafter, we measured the transfer characteristics of the device and demonstrate QD formation through a 2D plot depicting Coulomb diamonds. We also utilise COMSOL simulation to show no QD formation due to electrostatically defined gates on our device which implies that electron confinement caused by disordered potential. This was shown by taking a closer look at the gate spectroscopy data that was consistent with other similar published devices that displayed confinement due to disordered potential.