Gate-tunable spin-valley transport via carrier velocity in monolayer WSe$_2$
- URL: http://arxiv.org/abs/2606.12353v1
- Date: Wed, 10 Jun 2026 17:26:08 GMT
- Title: Gate-tunable spin-valley transport via carrier velocity in monolayer WSe$_2$
- Abstract summary: We investigate spin- and valley-resolved quantum transport in monolayer tungsten diselenide.<n>We show that the barrier velocity, scalar potential, incidence angle, incident energy, and barrier width serve as effective control parameters for transport.<n>These findings establish combined velocity and potential engineering as a powerful theoretical framework for controlling spin-valley physics in two-dimensional transition-metal dicogenides.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We theoretically investigate spin- and valley-resolved quantum transport in monolayer tungsten diselenide (WSe$_2$) described by an effective massive Dirac Hamiltonian. Particular attention is devoted to a finite barrier region characterized by simultaneously modulated Fermi velocity and scalar potential. The barrier velocity $v_2$ is related to the external velocity $v_1$ through a velocity ratio $ξ=v_2/v_1$, motivated by an optical analogy with the Snell-Descartes law. The exact refraction condition depends on the full spin- and valley-resolved dispersion, and the simple ratio $ξ=v_2/v_1$ is recovered only in the massless, symmetric limit. The interplay of intrinsic spin-orbit coupling in the conduction and valence bands, quantified by $λ_c$ and $λ_v$, with spin- and valley-dependent Zeeman fields, $M_s$ and $M_v$, gives rise to substantial changes in the quasiparticle dispersion, leading to pronounced modifications of the transport characteristics. By solving the Dirac equation and enforcing current-conserving matching conditions at the interfaces, we compute the spin- and valley-dependent transmission probability and conductance. Our results demonstrate that the barrier velocity, scalar potential, incidence angle, incident energy, and barrier width serve as effective control parameters for transport, giving rise to strong anisotropy and resonant tunneling features. Furthermore, we show that both the magnitude and orientation of spin- and valley-polarized currents can be continuously tuned via velocity and potential modulation. These findings establish combined velocity and potential engineering as a powerful theoretical framework for controlling spin-valley physics in two-dimensional transition-metal dichalcogenides.
Related papers
- Non-perturbative theory of valley splitting in Si qubits from variational wave function: periodic effects of shear strain and asymptotic freedom in the wiggle-well potential [0.0]
Valley splitting sets the energy scale at which spin and valley degrees of freedom hybridize in silicon quantum-well qubits.<n>We develop an analytical framework for treating non-perturbative effects of shear strain and wiggle-well potentials.
arXiv Detail & Related papers (2026-09-08T14:56:28Z) - Strain- and potential-controlled tunneling in monolayer MoS$_2$ [0.0]
We study spin- and valley-resolved quantum transport in monolayer MoS$$ under the combined influence of mechanical strain and an external scalar potential.<n>We show that the interplay between strain and electrostatic potential enables efficient control of both valley and spin polarization of the transmitted current.
arXiv Detail & Related papers (2026-07-06T07:57:39Z) - Lamb Shift of a Static Atom Facing a Rotating Surface [41.99844472131922]
We study how the Lamb shift of a static atom is modified when a nearby planar body rotates rigidly about its normal.<n>We first illustrate the formalism using a graphene sheet and then apply it to finite-thickness Drude and plasma conductors and to doped semiconductors.
arXiv Detail & Related papers (2026-07-01T21:49:04Z) - Tailoring pure valley-Zeeman spin-orbit coupling in WSe$_2$-encapsulated monolayer graphene [42.39722022913058]
Engineering proximity effects in twisted van der Waals heterostructures offers a powerful platform for designing electronic properties.<n>We report pure valley-Zeeman spin-orbit coupling in monolayer graphene, achieved by encapsulation between two parallel twisted WSe$$ monolayers.<n>We also demonstrate the ability to completely quench the proximity spin-orbit coupling by tuning the encapsulated geometry.
arXiv Detail & Related papers (2026-06-02T07:43:48Z) - Tuning quantum tunneling in WSe$_2$ via strain engineering [0.0]
We study strain-engineered quantum transport in monolayer tungsten diselenide (WSe$$) in the presence of an electrostatic scalar potential.<n>Our numerical analysis reveals that strain acts as a powerful tuning parameter that reshapes the electronic dispersion.<n>The ability to tailor polarization and interference effects suggests promising opportunities for the design of next-generation spintronic, valleytronic, and optoelectronic devices.
arXiv Detail & Related papers (2026-05-24T03:53:42Z) - Field-tunable spin-valley transport in monolayer MoS$_2$ [0.0]
We study field-controlled spin-valley transport in monolayer MoS$ polarized$ through a single electrostatic barrier.<n>By varying both the laser intensity (amplitude) and the polarization shape, we show that the same junction can be switched between valley resonance-selective operation.
arXiv Detail & Related papers (2026-05-20T06:37:27Z) - Symmetry-protected topology and deconfined solitons in a multi-link $\mathbb{Z}_2$ gauge theory [45.88028371034407]
We study a $mathbbZ$ lattice gauge theory defined on a multi-graph with links that can be visualized as great circles of a spherical shell.<n>We show that this leads to state-dependent tunneling amplitudes underlying a phenomenon analogous to the Peierls instability.<n>By performining a detailed analysis based on matrix product states, we prove that charge deconfinement emerges as a consequence of charge-fractionalization.
arXiv Detail & Related papers (2026-03-02T22:59:25Z) - Phase Transitions in Open Dicke Model: a degenerate perturbation theory approach [0.0]
We study the steady-state behavior of the open Dicke model, which describes the collective interaction of $N$ spin-$1/2$ particles with a lossy, quantized cavity mode.<n>While the standard model conserves total spin, Kirton and Keeling citePhysRevLett.118.123602 demonstrated that even infinitesimal homogeneous local dephasing destroys this phase transition.<n>We analyze this interplay using perturbation theory across subspaces of fixed total spin, $S$.
arXiv Detail & Related papers (2025-05-19T04:33:30Z) - Effect of disorder and strain on the operation of planar Ge hole spin qubits [0.34630926944621643]
Germanium quantum dots in strained $textGe/textSi_1-xtextGe_x$ heterostructures exhibit fast and coherent hole qubit control in experiments.<n>We numerically address the effects of random alloy disorder and gate-induced strain on the operation of planar Ge hole spin qubits.
arXiv Detail & Related papers (2025-02-10T19:00:03Z) - Harnessing Chiral Spin States in Molecular Nanomagnets for Quantum Technologies [44.1973928137492]
We show that chiral qubits naturally suppress always-on interactions that can not be switched off in weakly coupled qubits.<n>Our findings establish spin chirality engineering as a promising strategy for mitigating always-on interaction in entangling two chiral qubits in molecular quantum technologies.
arXiv Detail & Related papers (2025-01-21T08:23:12Z) - Thermal masses and trapped-ion quantum spin models: a self-consistent approach to Yukawa-type interactions in the $λ\!φ^4$ model [44.99833362998488]
A quantum simulation of magnetism in trapped-ion systems makes use of the crystal vibrations to mediate pairwise interactions between spins.
These interactions can be accounted for by a long-wavelength relativistic theory, where the phonons are described by a coarse-grained Klein-Gordon field.
We show that thermal effects, which can be controlled by laser cooling, can unveil this flow through the appearance of thermal masses in interacting QFTs.
arXiv Detail & Related papers (2023-05-10T12:59:07Z) - Spin Current Density Functional Theory of the Quantum Spin-Hall Phase [59.50307752165016]
We apply the spin current density functional theory to the quantum spin-Hall phase.
We show that the explicit account of spin currents in the electron-electron potential of the SCDFT is key to the appearance of a Dirac cone.
arXiv Detail & Related papers (2022-08-29T20:46:26Z) - Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit.
We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront.
The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
arXiv Detail & Related papers (2020-03-09T21:27:02Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.