Light-induced Floquet effects in graphene under continuous-wave mid-infrared irradiation

Light-matter interaction in 2D materials is predicted to induce Floquet-Bloch states with non-trivial topology [1,2,3,4]. We report on the observation of photoinduced longitudinal conductance and transverse voltage modifications in graphene Hall bars irradiated with high-power, linearly and circularly polarized mid-infrared radiation, at cryogenic temperatures. The radiation wavelength is 10.6 µm and the power density is larger than 1 mW/µm². We investigate the dependence of the photoresponse on temperature, Fermi level, and light polarization. We also characterize the sample photoresponse with a perpendicular magnetic field applied, including measurements of cyclotron resonance. These experiments will pave the way to studies of Floquet-Bloch edge states in materials with non-trivial topology, i.e. materials in the quantum Hall regime [5].





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