Ultrafast field control of symmetry, reciprocity, and reversibility in buckled graphene-like materials

TL;DR

This paper demonstrates that buckled 2D materials like silicene and germanene can be ultrafast optically controlled to exhibit non-reciprocal reflection, current generation, and reversible conduction, functioning akin to a light-controlled transistor.

Contribution

It introduces a theoretical framework showing ultrafast optical control of symmetry, reciprocity, and reversibility in buckled graphene-like materials using femtosecond pulses.

Findings

Non-reciprocal reflection and optical rectification predicted.

Electric currents generated parallel and normal to the in-plane field.

Reversibility of conduction band population controllable by field and phase.

Abstract

We theoretically show that buckled two-dimensional graphene-like materials (silicene and germanene) subjected to a femtosecond strong optical pulse can be controlled by the optical field component normal to their plane. In such strong fields, these materials are predicted to exhibit non-reciprocal reflection, optical rectification and generation of electric currents both parallel and normal to the in-plane field direction. Reversibility of the conduction band population is also field- and carrier-envelope phase controllable. There is a net charge transfer along the material plane that is also dependent on the normal field component. Thus a graphene-like buckled material behaves analogously to a field-effect transistor controlled and driven by the electric field of light with subcycle (femtosecond) speed.