  The aim of presented research is to design a nanodevice based on a
gate-defined quantum dot within a MoS$_2$ 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 (thus universal)
gates in a spin-valley two-qubit system. Through simulations we investigate
possibility of implementation of two qubits \textit{locally}, based on single
electron, with an intriguing feature that two-qubit gates are easier to realize
than single ones.
