Robust all-electrical topological valley filtering using monolayer 2D-Xenes

Abstract

We propose a realizable device design for an all-electrical robust valley filter that utilizes spin protected topological interface states hosted on monolayer 2D-Xene materials with large intrinsic spin-orbit coupling. In contrast with conventional quantum spin-Hall edge states localized around the $X$-points, the interface states appearing at the domain wall between topologically distinct phases are either from the $K$ or $K^{{}^{\prime }}$ points, making them suitable prospects for serving as valley-polarized channels. We show that the presence of a large band-gap quantum spin Hall effect enables the spatial separation of the spin-valley locked helical interface states with the valley states being protected by spin conservation, leading to a robustness against short-range non-magnetic disorder. By adopting the scattering matrix formalism on a suitably designed device structure, valley-resolved transport in the presence of non-magnetic short-range disorder for different 2D-Xene materials is also analyzed in detail. Our numerical simulations confirm the role of spin-orbit coupling in achieving an improved valley filter performance with a perfect quantum of conductance attributed to the topologically protected interface states. Our analysis further elaborates clearly the right choice of material, device geometry and other factors that need to be considered while designing an optimized valleytronic filter device.

11 pages, 7 figures, 2 tables. Comments welcome

References in corpus (18)

• Electric Field Effect in Atomically Thin Carbon Films
• Valley polarization in MoS2 monolayers by optical pumping
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• The Valley Hall Effect in MoS2 Transistors
• Valley filter and valley valve in graphene
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Valley-Polarized Metals and Quantum Anomalous Hall Effect in Silicene
• Generation of pure bulk valley current in graphene
• Germanene termination of Ge${}_2$Pt crystals on Ge(110)
• Non-equilibrium Green s function based model for dephasing in quantum transport
• Light-Induced Valleytronics in Pristine Graphene
• Valley-polarized quantum anomalous Hall phase and disorder induced valley-filtered chiral edge channels
• Quantum Spin-Valley Hall Kink States: From Concept to Materials Design
• The valley filter efficiency of monolayer graphene and bilayer graphene line defect model
• Pure spin current and perfect valley filter by designed separation of the chiral states in two-dimensional honeycomb lattices
• Incoherent scattering can favorably influence energy filtering in nanostructured thermoelectrics
• Role of dephasing on the conductance signatures of Majorana zero modes
• Momentum relaxation effects in 2D-Xene field effect device structures

Cited by in corpus (7)

• 2024 roadmap on 2D topological insulators
• Controlling Valley-Polarisation in Graphene via Tailored Light Pulses
• High-Order Topological Phase Diagram Revealed by Anomalous Nernst Effect in Janus ScClI Monolayer
• Effectuating tunable valley selection via multi-terminal monolayer graphene devices
• Tight-Binding Device Modeling of 2-D Topological Insulator Field-Effect Transistors With Gate-Induced Phase Transition
• Interface engineering of van der Waals heterostructures towards energy-efficient quantum devices operating at high temperatures
• Proposal for a solid-state magnetoresistive Larmor quantum clock