Floquet Weyl Semimetal Induced by Off-Resonant Light

TL;DR

This paper demonstrates that off-resonant light can induce a Floquet Weyl semimetal state in three-dimensional topological insulators by renormalizing the Dirac mass through virtual photon processes, offering a new method to realize topological semimetals.

Contribution

It introduces a novel mechanism using off-resonant light to create Floquet Weyl semimetals in topological insulators, distinct from on-resonant light approaches.

Findings

Off-resonant light induces a Floquet Weyl semimetal state.

Virtual photon processes are key to renormalizing the Dirac mass.

The mechanism differs from on-resonant light methods.

Abstract

We propose that a Floquet Weyl semimetal state can be induced in three-dimensional topological insulators, either nonmagnetic or magnetic, by the application of off-resonant light. The virtual photon processes play a critical role in renormalizing the Dirac mass and so resulting in a topological semimetal with vanishing gap at Weyl points. The present mechanism via off-resonant light is quite different from that via on-resonant light, the latter being recently suggested to give rise to a Floquet topological state in ordinary band insulators.