Quantum circularly polarized light steers electrons in graphene

Daniel M. B. Lesko, Tobias Weitz, Simon Wittigschlager, Weizhe Li, Christian Heide, Ofer Neufeld, and Peter Hommelhoff, affiliated with Friedrich-Alexander-Universität Erlangen-Nürnberg, the University of Central Florida, the Technion – Israel Institute of Technology, and the Max Planck Institute for the Structure and Dynamics of Matter, have demonstrated optical control of electrons within light-dressed graphene, a capability previously difficult to achieve in light-dressed band structures. By focusing circularly polarized femtosecond laser pulses on monolayer graphene, the team generated a Floquet topological insulator, a state of matter exhibiting unique quantum properties. They observed photocurrent circular dichroism, the all-optical anomalous Hall effect, and FTI valley-polarized currents, which could enable ultrafast…