Valley two-qubit system in a MoS${}_2$-monolayer gated double quantum dot

Abstract

We explore a two-qubit system defined on valley isospins of two electrons confined in a gate-defined double quantum dot created within a MoS${}_2$ monolayer flake. We show how to initialize, control, interact and read out such valley qubits only by electrical means using voltages applied to the local planar gates, which are layered on the top of the flake. By demonstrating the two-qubit exchange or readout via the Pauli blockade, we prove that valley qubits in transition-metal-dichalcogenide semiconductors family fulfill the universality criteria and represent a scalable quantum computing platform. Our numerical experiments are based on the tight-binding model for a MoS${}_2$ monolayer, which gives single-electron eigenstates that are then used to construct a basis of Slater-determinants for the two-electron configuration space. We express screened electron-electron interactions in this basis by calculating the Coulomb matrix elements using localized Slater-type orbitals. Then we solve the time-dependent Schrödinger equation and obtain an exact time-evolution of the two-electron system. During the evolution we simultaneously solve the Poison equation, finding the confinement potential controlled via voltages applied to the gates.

15 pages, 12 figures

References in corpus (14)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Valley polarization in MoS2 monolayers by optical pumping
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2
• Graphene Nanobubbles as Valley Filters and Beamsplitters
• Rapid high-fidelity gate-based spin read-out in silicon
• Valley-spin blockade and spin resonance in carbon nanotubes
• Intervalley coupling by quantum dot confinement potentials in monolayer transition metal dichalcogenides
• Gate-defined, Accumulation-mode Quantum Dots in Monolayer and Bilayer WSe${}_2$
• Calculation of two-centre two-electron integrals over Slater-type orbitals revisited. I. Coulomb and hybrid integrals
• Valley and spin polarized broken symmetry states of interacting electrons in gated MoS${}_2$ quantum dots
• Valley-selective energy transfer between quantum dots in atomically thin semiconductors
• Two-electron n-p double quantum dots in carbon nanotubes
• Theory of field-modulated spin-valley-orbital pseudospin physics

Cited by in corpus (7)

• Nanomaterials for Quantum Information Science and Engineering
• Gate-Controlled Quantum Dots Based on Two-Dimensional Materials
• Coherent exciton-exciton interactions and exciton dynamics in a MoSe\textsubscript{2}/WSe\textsubscript{2} heterostructure
• Spin-valley locking for in-gap quantum dots in a MoS2 transistor
• Interacting holes in a gated WSe${}_2$ quantum channel: valley correlations and zigzag Wigner crystal
• Electrically tunable MoSe${}_2$/WSe${}_2$ heterostructure-based quantum dot
• Spin-valley qubits in gated quantum dots in a single layer of transition metal dichalcogenides