Floquet Weyl semimetal induced by off-resonant light

Abstract

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