Transport properties of non-equilibrium systems under the application of   light: Photo-induced quantum Hall insulators without Landau levels
  In this paper, we study transport properties of non-equilibrium systems under the application of light in many-terminal measurements, using the Floquet picture. We propose and demonstrate that the quantum transport properties can be controlled in materials such as graphene and topological insulators, via the application of light. Remarkably, under the application of off-resonant light, topological transport properties can be induced; these systems exhibits quantum Hall effects in the absence of a magnetic field with a near quantization of the Hall conductance, realizing so-called quantum Hall systems without Landau levels first proposed by Haldane. 
Takuya Kitagawa, Takashi Oka, Arne Brataas, Liang Fu, Eugene Demler
cond-mat.mes-hall cond-mat.quant-gas