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

TL;DR

This paper investigates how a linearly polarized laser field influences quantum tunneling in monolayer WSe$_2$, revealing controllable suppression of transmission and potential for optoelectronic device applications.

Contribution

It introduces a Floquet formalism-based analytical approach to study laser-driven tunneling in WSe$_2$, highlighting the dynamic control of quantum transport via light-matter interaction.

Findings

Laser field induces multiple Floquet sidebands increasing with driving strength.

Significant suppression of transmission due to Floquet interference effects.

Enhanced control of tunneling and energy states through laser parameters.

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 B\"uttiker approach. Our results reveal that the laser field induces a rich Floquet sideband structure, whose number and strength increase with the driving parameter $\alpha$. 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.