Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2605.11737

Laser-assisted tunneling in a static tungsten diselenide WSe$_2$ barrier

Rachid El Aitouni, Mohammed El Azar, Clarence Cortes, Pablo Díaz, David Laroze, Ahmed Jellal

cond-mat.mes-hallquant-phSubmitted May 12, 2026• Announced May 13, 2026
arXivHTMLPDF

Abstract

We study the tunneling effect of Dirac fermions in a monolayer WSe$_2$ subjected to a static electrostatic barrier and irradiated by a linearly polarized laser field. Within the Floquet formalism, the time-periodic driving is incorporated to derive analytical wave functions across the three regions of the system. By enforcing continuity conditions at the interfaces, we obtain the transmission and reflection coefficients, which are then used to evaluate the conductance via the Büttiker approach. Our results reveal that the laser field induces a rich Floquet sideband structure, whose number and strength increase with the driving parameter $α$. This leads to a significant suppression of transmission and provides an efficient mechanism to overcome Klein tunneling. Moreover, increasing the width of the irradiated region enhances the interaction between fermions and the external field, resulting in energy renormalization and the formation of Stark-like confined states. The interaction between several Floquet channels creates strong interference effects, which reduce the transmitted current even further. The results demonstrate that light-matter interaction allows for the dynamic control of quantum transport in WSe$_2$ materials. This technology allows for the development of new optoelectronic devices, including tunable quantum filters and light-controlled nanoscale transistors.

Comments
12 pages, 7 figures. Version to appear in Ann. Phys. 2026

Related papers

Tuning quantum tunneling in WSe$_2$ via strain engineering

Rachid El Aitouni, Hasna Chnafa, Clarence Cortes +2 more

We present a comprehensive theoretical study of strain-engineered quantum transport in monolayer tungsten diselenide (WSe$_2$) in the presence of an electrostatic scalar potential. By incorporating strain effects within a low-energy Dirac framework, we analyze their impact on spin- and valley-resolved transmission, conductance, and polarization. The applied potential barrier partitions the system into three distinct regions, allowing for an analytical derivation of the wave functions in each domain. Enforcing continuity conditions at the interfaces yields exact expressions for the transmission and reflection amplitudes. The transmission probability is evaluated from the corresponding current densities, while the conductance is obtained using the Landauer-Büttiker formalism, enabling a quantitative determination of spin and valley polarizations. Our numerical analysis reveals that strain acts as a powerful tuning parameter that reshapes the electronic dispersion and strongly modifies transport characteristics. In particular, the transmission and conductance exhibit pronounced oscillatory behavior driven by quantum interference and resonant tunneling mechanisms. More importantly, both spin and valley polarizations display substantial and highly controllable variations as functions of strain, barrier height, and incident energy. These results demonstrate that strain and electrostatic engineering provide an efficient and versatile platform for manipulating spin-valley degrees of freedom in WSe$_2$. The ability to tailor polarization and interference effects suggests promising opportunities for the design of next-generation spintronic, valleytronic, and optoelectronic devices based on two-dimensional transition-metal dichalcogenides.

cond-mat.mes-hallCross-listedarXiv:2605.24851•May 26, 2026

Floquet-driven tunneling control in monolayer MoS$_2$

Rachid El Aitouni, Aotmane En Naciri, Clarence Cortes +2 more

We study how fermions in molybdenum disulfide MoS$_2$ interact with a laser field and a static potential barrier, focusing on the transmission probability. Our aim is to understand and control photon-assisted quantum transport in this two-dimensional material under external driving. We use the Floquet approximation to describe the wave functions in the three regions of the system. By applying continuity conditions at the boundaries, we obtain a set of equations involving an infinite number of Floquet modes. We explicitly determine transmissions involving the central band $E$ and the first sidebands $E \pm \hbarω$. As for higher-order bands, we use the transfer matrix approach together with current density to compute the associated transmissions. Our results reveal that the transmission probability oscillates for both spin-up and spin-down electrons. The oscillations of spin-down electrons occur over nearly twice the period of spin-up electrons. Among all bands, the central one consistently shows the highest transmission. We also find that stronger laser fields and wider barriers both lead to reduced transmission. Moreover, laser irradiation enables controllable channeling and filtering of transmission bands by tuning the laser intensity and system parameters. This highlights the potential of laser-driven MoS$_2$ structures for highly sensitive electromagnetic sensors and advanced optoelectronic devices.

cond-mat.mes-hallCross-listedarXiv:2601.04837•Jan 9, 2026

Confinement in a magnetically induced WSe$_2$ quantum dots

Rachid El Aitouni, Mohammed El Azar, Clarence Cortes +2 more

Monolayer tungsten diselenide (WSe$_2$) has become a suitable platform for quantum transport and spintronics and valleytronics applications because it possesses an intrinsic band gap and strong spin-orbit coupling and spin-valley coupling features. The electrostatic confinement of Dirac fermions proves challenging in graphene because of Klein tunneling, yet WSe$_2$ provides an environment that supports both carrier localization and the development of confined quantum states. In this work, we theoretically investigate the confinement of massive Dirac fermions in a WSe$_2$ quantum dot generated by a localized magnetic field. Using the effective Dirac Hamiltonian in the presence of a magnetic flux, we derive the exact wave functions and scattering coefficients by employing Kummer's confluent hypergeometric functions together with Bessel and Hankel functions. Our results show that the localized magnetic field provides an efficient mechanism to suppress Klein tunneling and promote the formation of stable quasibound states. We systematically examine the scattering efficiency and carrier density distributions as functions of the incident energy, magnetic field strength, and quantum dot radius. We find that low-energy carriers are strongly confined by the magnetic barrier, while the interplay between magnetic localization and geometric confinement gives rise to sharp and tunable resonance peaks. These results provide valuable insight into the control of spin-valley transport in transition metal dichalcogenide nanostructures and establish a theoretical basis for the development of quantum confinement devices and quantum information technologies.

cond-mat.mes-hallCross-listedarXiv:2607.01192•Jul 2, 2026

Laser-induced modulation of conductance in graphene with magnetic barriers

Rachid El Aitouni, Miloud Mekkaoui, Pablo Díaz +2 more

We study how electrons move across a graphene sheet when it encounters two magnetic barriers with a region in between that is continuously driven by laser light. Rather than acting as a static obstacle, this illuminated middle section becomes a Floquet cavity that opens new transport channels through controlled photon absorption and emission. By combining Floquet theory with the transfer matrix method, we track electron transmission through both the main energy band and the emerging photon-assisted sidebands. We find that the laser does more than modify the potential--it reshapes how electrons interact between the magnetic barriers, enabling a switch from ordinary transmission to transport dominated by photon exchange. Because the magnetic field and the optical drive are applied to separate sections of the device, the system supports interference between cyclotron-filtered motion and discrete photon-pumping channels, producing Fano resonances and angle-dependent transmission zeros that cannot appear in double magnetic or double laser barrier systems alone. Under well-defined conditions, the distance between the magnetic barriers controls the coupling between Floquet channels, allowing highly tunable resonances and even perfect transmission, despite strong magnetic confinement. We also observe that low-energy carriers are efficiently blocked by the magnetic regions, while conductance steadily rises with energy until it reaches a clear saturation plateau. This hybrid design provides a versatile way to steer graphene electrons by balancing optical pumping and magnetic momentum filtering.

cond-mat.mes-hallCross-listedarXiv:2512.03863•Dec 4, 2025

Gate-tunable spin-valley transport via carrier velocity in monolayer WSe$_2$

Otman Bouladiane, Hocine Bahlouli, Clarence Cortes +2 more

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.

cond-mat.mes-hallCross-listedarXiv:2606.12353•Jun 11, 2026

Field-tunable spin-valley transport in monolayer MoS$_2$

Kamal Azaidaoui, Hocine Bahlouli, Clarence Cortes +2 more

We study field-controlled spin-valley transport in monolayer MoS$_2$ through a single electrostatic barrier and a uniform off-resonant elliptically polarized irradiation. Starting from the massive Dirac Hamiltonian with intrinsic spin-orbit coupling, we use a high-frequency Floquet expansion to obtain an effective static model with a laser-renormalized mass (gap) term. We solve the scattering problem by spinor matching and derive the exact analytic expression for the transmission. The numerical results show that the drive tunes both the spin-valley-dependent propagation threshold inside the barrier and the Fabry-Pérot phase, creating controllable pass/stop bands. By varying both the laser intensity (amplitude) and the polarization shape, we show that the same junction can be switched between broadband valley filtering and resonance-selective operation, and the valley contrast remains visible in the Landauer conductance. Our findings establish an efficient route for realizing optically reconfigurable valleytronic and spintronic functionalities in MoS$_2$.

cond-mat.mes-hallCross-listedarXiv:2605.20790•May 21, 2026
Laser-assisted tunneling in a static tungsten diselenide WSe2_22​ barrier
We study the tunneling effect of Dirac fermions in a monolayer WSe2_22​ subjected to a static electrostatic barrier and irradiated by a linearly polarized laser field. Within the Floquet formalism, the time-periodic driving is incorporated to derive analytical wave functions across the three regions of the system. By enforcing continuity conditions at the interfaces, we obtain the transmission and reflection coefficients, which are then used to evaluate the conductance via the Büttiker approach. Our results reveal that the laser field induces a rich Floquet sideband structure, whose number and strength increase with the driving parameter ααα. This leads to a significant suppression of transmission and provides an efficient mechanism to overcome Klein tunneling. Moreover, increasing the width of the irradiated region enhances the interaction between fermions and the external field, resulting in energy renormalization and the formation of Stark-like confined states. The interaction between several Floquet channels creates strong interference effects, which reduce the transmitted current even further. The results demonstrate that light-matter interaction allows for the dynamic control of quantum transport in WSe2_22​ materials. This technology allows for the development of new optoelectronic devices, including tunable quantum filters and light-controlled nanoscale transistors.
Tuning quantum tunneling in WSe2_22​ via strain engineering
We present a comprehensive theoretical study of strain-engineered quantum transport in monolayer tungsten diselenide (WSe2_22​) in the presence of an electrostatic scalar potential. By incorporating strain effects within a low-energy Dirac framework, we analyze their impact on spin- and valley-resolved transmission, conductance, and polarization. The applied potential barrier partitions the system into three distinct regions, allowing for an analytical derivation of the wave functions in each domain. Enforcing continuity conditions at the interfaces yields exact expressions for the transmission and reflection amplitudes. The transmission probability is evaluated from the corresponding current densities, while the conductance is obtained using the Landauer-Büttiker formalism, enabling a quantitative determination of spin and valley polarizations. Our numerical analysis reveals that strain acts as a powerful tuning parameter that reshapes the electronic dispersion and strongly modifies transport characteristics. In particular, the transmission and conductance exhibit pronounced oscillatory behavior driven by quantum interference and resonant tunneling mechanisms. More importantly, both spin and valley polarizations display substantial and highly controllable variations as functions of strain, barrier height, and incident energy. These results demonstrate that strain and electrostatic engineering provide an efficient and versatile platform for manipulating spin-valley degrees of freedom in WSe2_22​. The ability to tailor polarization and interference effects suggests promising opportunities for the design of next-generation spintronic, valleytronic, and optoelectronic devices based on two-dimensional transition-metal dichalcogenides.
Floquet-driven tunneling control in monolayer MoS2_22​
We study how fermions in molybdenum disulfide MoS2_22​ interact with a laser field and a static potential barrier, focusing on the transmission probability. Our aim is to understand and control photon-assisted quantum transport in this two-dimensional material under external driving. We use the Floquet approximation to describe the wave functions in the three regions of the system. By applying continuity conditions at the boundaries, we obtain a set of equations involving an infinite number of Floquet modes. We explicitly determine transmissions involving the central band EEE and the first sidebands E±ℏωE \pm \hbarωE±ℏω. As for higher-order bands, we use the transfer matrix approach together with current density to compute the associated transmissions. Our results reveal that the transmission probability oscillates for both spin-up and spin-down electrons. The oscillations of spin-down electrons occur over nearly twice the period of spin-up electrons. Among all bands, the central one consistently shows the highest transmission. We also find that stronger laser fields and wider barriers both lead to reduced transmission. Moreover, laser irradiation enables controllable channeling and filtering of transmission bands by tuning the laser intensity and system parameters. This highlights the potential of laser-driven MoS2_22​ structures for highly sensitive electromagnetic sensors and advanced optoelectronic devices.
Confinement in a magnetically induced WSe2_22​ quantum dots
Monolayer tungsten diselenide (WSe2_22​) has become a suitable platform for quantum transport and spintronics and valleytronics applications because it possesses an intrinsic band gap and strong spin-orbit coupling and spin-valley coupling features. The electrostatic confinement of Dirac fermions proves challenging in graphene because of Klein tunneling, yet WSe2_22​ provides an environment that supports both carrier localization and the development of confined quantum states. In this work, we theoretically investigate the confinement of massive Dirac fermions in a WSe2_22​ quantum dot generated by a localized magnetic field. Using the effective Dirac Hamiltonian in the presence of a magnetic flux, we derive the exact wave functions and scattering coefficients by employing Kummer's confluent hypergeometric functions together with Bessel and Hankel functions. Our results show that the localized magnetic field provides an efficient mechanism to suppress Klein tunneling and promote the formation of stable quasibound states. We systematically examine the scattering efficiency and carrier density distributions as functions of the incident energy, magnetic field strength, and quantum dot radius. We find that low-energy carriers are strongly confined by the magnetic barrier, while the interplay between magnetic localization and geometric confinement gives rise to sharp and tunable resonance peaks. These results provide valuable insight into the control of spin-valley transport in transition metal dichalcogenide nanostructures and establish a theoretical basis for the development of quantum confinement devices and quantum information technologies.
We study how electrons move across a graphene sheet when it encounters two magnetic barriers with a region in between that is continuously driven by laser light. Rather than acting as a static obstacle, this illuminated middle section becomes a Floquet cavity that opens new transport channels through controlled photon absorption and emission. By combining Floquet theory with the transfer matrix method, we track electron transmission through both the main energy band and the emerging photon-assisted sidebands. We find that the laser does more than modify the potential--it reshapes how electrons interact between the magnetic barriers, enabling a switch from ordinary transmission to transport dominated by photon exchange. Because the magnetic field and the optical drive are applied to separate sections of the device, the system supports interference between cyclotron-filtered motion and discrete photon-pumping channels, producing Fano resonances and angle-dependent transmission zeros that cannot appear in double magnetic or double laser barrier systems alone. Under well-defined conditions, the distance between the magnetic barriers controls the coupling between Floquet channels, allowing highly tunable resonances and even perfect transmission, despite strong magnetic confinement. We also observe that low-energy carriers are efficiently blocked by the magnetic regions, while conductance steadily rises with energy until it reaches a clear saturation plateau. This hybrid design provides a versatile way to steer graphene electrons by balancing optical pumping and magnetic momentum filtering.
Gate-tunable spin-valley transport via carrier velocity in monolayer WSe2_22​
We theoretically investigate spin- and valley-resolved quantum transport in monolayer tungsten diselenide (WSe2_22​) 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 v2v_2v2​ is related to the external velocity v1v_1v1​ through a velocity ratio ξ=v2/v1ξ=v_2/v_1ξ=v2​/v1​, 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=v2/v1ξ=v_2/v_1ξ=v2​/v1​ is recovered only in the massless, symmetric limit. The interplay of intrinsic spin-orbit coupling in the conduction and valence bands, quantified by λcλ_cλc​ and λvλ_vλv​, with spin- and valley-dependent Zeeman fields, MsM_sMs​ and MvM_vMv​, 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.
Field-tunable spin-valley transport in monolayer MoS2_22​
We study field-controlled spin-valley transport in monolayer MoS2_22​ through a single electrostatic barrier and a uniform off-resonant elliptically polarized irradiation. Starting from the massive Dirac Hamiltonian with intrinsic spin-orbit coupling, we use a high-frequency Floquet expansion to obtain an effective static model with a laser-renormalized mass (gap) term. We solve the scattering problem by spinor matching and derive the exact analytic expression for the transmission. The numerical results show that the drive tunes both the spin-valley-dependent propagation threshold inside the barrier and the Fabry-Pérot phase, creating controllable pass/stop bands. By varying both the laser intensity (amplitude) and the polarization shape, we show that the same junction can be switched between broadband valley filtering and resonance-selective operation, and the valley contrast remains visible in the Landauer conductance. Our findings establish an efficient route for realizing optically reconfigurable valleytronic and spintronic functionalities in MoS2_22​.