Experimental study of strong light-matter interaction in graphene Hall bar devices

Strong light-matter interaction in graphene is predicted to induce Floquet-Bloch states which may also have non-trivial topology [1,2,3]. We report on the experimental observation of photoinduced transversal voltage and photoinduced current in graphene Hall bars irradiated with high-power linearly and circularly-polarized mid-Infrared radiation at cryogenic temperatures. The radiation wavelength is 10.6 microns and the power density is larger than 1 mW/micron^2. We measure the dependence of the photoresponse on the gate voltage, temperature, and light polarization.

References:

[1] T. Oka, H. Aoki, Phys. Rev. B 79, 081406(R) (2009).

[2] H. Calvo et al., Appl. Phys. Lett. 98, 232103 (2011); L. E. F. Foa Torres et al. Phys. Rev. Lett. 113, 266801 (2014).

[3] J. McIver et al., Nat. Phys. 16, 38 (2020).