Special QM Seminar

Light-dressed materials offer immense potential for new electronic properties by altering their band structures, resulting in various quantum and topological phenomena. Achieving optical control of electrons in these systems has been challenging. Here, we demonstrate such control in light-dressed graphene. Using circularly polarized femtosecond laser pulses at 1550 nm, we transform monolayer graphene into a Floquet topological insulator (FTI). With a phase-locked second harmonic field, we dynamically manipulate electrons in this state. For the first time, we observe photocurrent circular dichroism, the all-optical anomalous Hall effect, and FTI valley-polarized currents, promising advancements in topological electronics, spectroscopy, and attosecond physics.