Abstract
The aim of presented research is to design a nanodevice based on a gate-defined quantum dot within a MoS2 monolayer in which we confine a single electron. By applying control voltages to the device gates we modulate the confinement potential and force intervalley transitions. The present Rashba spin–orbit coupling additionally allows for spin operations. Moreover, both effects enable the spin-valley SWAP. The device structure is modeled realistically, taking into account feasible dot-forming potential and electric field that controls the Rasha coupling. Therefore, by performing reliable numerical simulations, we show how by electrically controlling the state of the electron in the device, we can obtain single- and two-qubit gates in a spin-valley two-qubit system. Through simulations we investigate possibility of implementation of two qubits locally, based on single electron, with an intriguing feature that two-qubit gates are easier to realize than single ones.
Highlights
Two-dimensional crystals consisting of single layers of atoms are modern materials that can be used for implementation of quantum computation. 2D monolayers of transition metal dichalcogenides (TMDCs), e.g. MoS2, seem to be better candidates than graphene because of their wide band gaps and strong electrically induced spinorbit coupling of the Rashba type[1,2]
Methods for building devices based on gated TMDC monolayers or nanotubes become increasingly advanced[13,14,15,16,17], opening the possibility of utilizing the spin and valley index of electrons controlled therein
It is shown by recent results with electrostatic quantum dots (QDs) with a gated MoS2-nanoribbon-QD measured by a single electron transport[18,19], or tunable TMDC spintronic devices, where spin or valley polarized currents emerge in TMDC monolayer proximitized by nearby ferromagnetic[20,21,22,23,24]
Summary
Two-dimensional crystals consisting of single layers of atoms are modern materials that can be used for implementation of quantum computation. 2D monolayers of transition metal dichalcogenides (TMDCs), e.g. MoS2, seem to be better candidates than graphene because of their wide band gaps and strong electrically induced spinorbit coupling of the Rashba type[1,2]. Methods for building devices based on gated TMDC monolayers or nanotubes become increasingly advanced[13,14,15,16,17], opening the possibility of utilizing the spin and valley index of electrons controlled therein. We examined the possibility of realization of a nanodevice based on a MoS2 monolayer, capable of creating a two-qubit system defined on spin and valley degrees of freedom of a confined electron. Voltages applied to these gates (relative to the substrate) are used to create confinement in the flake. Plete the electron gas until a single electron remains in the formed dot confinement potential
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