Large valley splitting in monolayer WS${}_2$ by proximity coupling to an insulating antiferromagnetic substrate

Abstract

Lifting the valley degeneracy is an efficient way to achieve valley polarization for further valleytronics operations. In this work, we demonstrate that a large valley splitting can be obtained in monolayer transition metal dichalcogenides by magnetic proximity coupling to an insulating antiferromagnetic substrate. As an example, we perform first-principles calculations to investigate the electronic structures of monolayer WS${}_2$ on the MnO(111) surface. Our calculation results suggest that a large valley splitting of 214 meV, which corresponds to a Zeeman magnetic field of 1516 T, is induced in the valence band of monolayer WS${}_2$. The magnitude of valley splitting relies on the strength of interfacial orbital hybridization, and can be continually tuned by applying an external out-of-plane pressure and in-plane strain. More interestingly, we find that both spin and valley index will flip when the magnetic ordering of MnO is reversed. Besides, owing to the sizeable Berry curvature and time-reversal symmetry breaking in the WS${}_2$/MnO heterostructure, a spin and valley polarized anomalous Hall current can be generated in the presence of an in-plane electric field, which allow one to detect valleys by the electrical approach. Our results shed light on the realization of valleytronic devices using the antiferromagnetic insulator as the substrate.

7pages,6figures

References in corpus (12)

• Valley polarization in MoS2 monolayers by optical pumping
• Valley filter and valley valve in graphene
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• First Principles Calculation of Anomalous Hall Conductivity in Ferromagnetic bcc Fe
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Breaking of valley degeneracy by magnetic field in monolayer MoSe2
• Valley Splitting and Polarization by the Zeeman Effect in Monolayer MoSe2
• Spin-Valleytronics in Silicene: Quantum-Spin-Quantum-Anomalous Hall Insulators and Single-Valley Semimetals
• Intrinsic spin Hall effect in monolayers of group-VI dichalcogenides: A first-principles study
• Pressure induced metallization with absence of structural transition in layered MoSe2
• Controlling the Schottky barrier at MoS2|metal contacts by inserting a BN monolayer

Cited by in corpus (17)

• Valley-related multiple Hall effect in single-layer VSi2P4
• Multifunctional Two-dimensional van der Waals Janus Magnet Cr-based Dichalcogenide Halides
• Protected valley states and generation of valley- and spin-polarized current in monolayer MA2Z4
• Strain-driven valley states and phase transitions in Janus VSiGeN4 monolayer
• Giant proximity exchange and valley splitting in transition metal dichalcogenide/$h\mathrm{BN}$/(Co, Ni) heterostructures
• Strong manipulation of the valley splitting upon twisting and gating in MoSe${}_2$/CrI${}_3$ and WSe${}_2$/CrI${}_3$ van der Waals heterostructures
• Electrically switchable valley polarization, spin/valley filter, and valve effects in transition-metal dichalcogenide monolayers interfaced with two-dimensional ferromagnetic semiconductors
• Excitonic Magneto-Optical Kerr Effect in 2D Transition Metal Dichalcogenides Induced by Spin Proximity
• Proximity spin-orbit and exchange coupling in ABA and ABC trilayer graphene van der Waals heterostructures
• Effects of substrate-surface reconstruction and orientation on spin-valley polarization in MoTe${}_2$/EuO
• Controllable phase transitions between multiple charge density waves in monolayer 1T-VSe${}_2$ via doping and strain engineering
• Manipulating Spin-Lattice Coupling in Layered Magnetic Topological Insulator Heterostructure $via$ Interface Engineering
• Topological Interlayer Superconductivity in a van der Waals Heterostructure
• Valley-polarization and stable triplet exciton formation in 2D lateral heterostrcuture of hBN-kagome and graphene
• Spin Pumping into two-dimensional systems
• Spin dependent charge transfer in MoSe2/hBN/Ni hybrid structures
• Quantum oscillations of valley current driven by microwave irradiation in transition-metal dichalcogenide/ferromagnet hybrids