Coherent destruction of tunneling in graphene irradiated by elliptically polarized lasers

TL;DR

This paper theoretically investigates how elliptically polarized lasers can control photo-induced transitions in graphene, revealing a new way to suppress multiphoton resonances through Floquet engineering.

Contribution

It demonstrates that laser ellipticity can be used as a control parameter to selectively suppress tunneling in graphene, advancing understanding of Floquet-induced phenomena.

Findings

Ellipticity influences avoided crossing structures in Floquet quasi-energy levels.

Laser strength and ellipticity affect transition probabilities in graphene.

Ellipticity enables selective suppression of multiphoton resonances.

Abstract

Photo-induced transition probabilities in graphene are studied theoretically from the viewpoint of Floquet theory. Conduction band populations are computed for a strongly, periodically driven graphene sheet under linear, circular, and elliptic polarization. Features of the momentum spectrum of excited quasi-particles can be directly related to the avoided crossing of the Floquet quasi-energy levels. In particular, the impact of the ellipticity and the strength of the laser excitation on the avoided crossing structure -- and on the resulting transition probabilities -- is studied. It is shown that the ellipticity provides an additional control parameter over the phenomenon of coherent destruction of tunneling in graphene, allowing one to selectively suppress multiphoton resonances.