Intrinsic valley Hall transport in atomically thin MoS2

Abstract

Electrons hopping in two-dimensional honeycomb lattices possess a valley degree of freedom in addition to charge and spin. In the absence of inversion symmetry, these systems were predicted to exhibit opposite Hall effects for electrons from different valleys. Such valley Hall effects have been achieved only by extrinsic means, such as substrate coupling, dual gating, and light illuminating. Here, we report the first observation of intrinsic valley Hall transport without any extrinsic symmetry breaking in the non-centrosymmetric monolayer and trilayer MoS2, evidenced by considerable nonlocal resistance that scales cubically with local resistance. Such a hallmark survives even at room temperature with a valley diffusion length at micron scale. By contrast, no valley Hall signal is observed in the centrosymmetric bilayer MoS2. Our work elucidates the topological quantum origin of valley Hall effects and marks a significant step towards the purely electrical control of valley degree of freedom in topological valleytronics.

arXiv comment22 pages, 4 figures

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• Orbital Hall effect in bilayer transition metal dichalcogenides: From the intra-atomic approximation to the Bloch states orbital magnetic moment approach
• Tunable large Berry dipole in strained twisted bilayer graphene
• Highly tunable nonlinear Hall effects induced by spin-orbit couplings in strained polar transition-metal dichalcogenides
• Long-range nontopological edge currents in charge-neutral graphene
• Dielectrics for Two-Dimensional Transition Metal Dichalcogenide Applications
• Moiré Band Topology in Twisted Bilayer Graphene
• Emergent properties of van der Waals bilayers revealed by computational stacking
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• Gate-Controlled Quantum Dots Based on Two-Dimensional Materials
• Valley Degree of Freedom in Two-Dimensional van der Waals Materials
• Orbital magnetoelectric effect in nanoribbons of transition metal dichalcogenides
• Valley contrasting bulk photovoltaic effect in antiferromagnetic MnPSe${}_3$ monolayer
• Topological Valley Transport of Gapped Dirac Magnons in Bilayer Ferromagnetic Insulators
• Giant nonlocal edge conduction in the axion insulator state of MnBi2Te4
• Orbitronics in Two-dimensional Materials
• Valley polarized current and resonant electronic transport in a non-uniform ${\mathbf{MoS}}_2$ zigzag nanoribbon
• Signature of spin-resolved quantum point contact in p-type trilayer WSe${}_2$ van der Waals heterostructure
• Epitaxially defined Luttinger liquids on MoS${}_2$ bicrystals
• Emergent inhomogeneity and non-locality in a graphene field-effect transistor on a near-parallel moire superlattice of transition metal dichalcogenides
• Spin Torque Generated by Valley Hall Effect in WSe2
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• Impact of novel electron-phonon coupling mechanisms on valley physics in two-dimensional materials
• Geometric band properties in strained monolayer transition metal dichalcogenides using simple band structures
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• Valley spin-acoustic resonance in MoS${}_2$ monolayers
• Theory of Nonlocal Transport from Nonlinear Valley Responses
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• Spin Pumping into two-dimensional systems
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• Tunable atomically enhanced moiré Berry curvatures in twisted triple bilayer graphene
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• Hexagonal boron nitride/bilayer graphene moiré superlattices in the Dirac-material family: energy-band engineering and carrier doping by dual gating
• Surface acoustic wave-driven valley current generation in intervalley coherent states
• Semiconductor Meta-Graphene and Valleytronics
• All-electrical valley filtering in graphene systems (II): Numerical study of electron transport in valley valves
• Intrinsic nonlinear valley Nernst effect