Graphene, a monolayer of carbon atoms arranged in a hexagonal lattice demonstrates fascinating transport and optical effects. Many phenomena in this material stem from the linear, Dirac-like, dispersion of electron energy realized in the vicinity of Brillouin zone edges compared with parabolic dispersion in widespread semiconductors.
I present a review of the nonlinear optical and optoelectronic properties of graphene. The main emphasis is put on the processes of harmonic generation, frequency mixing, photon drag and photogalvanic effects. The physical mechanisms controlling non-linear transport are described in depth including phenomenological description based on symmetry arguments, models visualizing physics of nonlinear responses, and microscopic theory of individual effects.
It is demonstrated that due to strong non-linearity related with Dirac-like energy spectrum the graphene is a material of choice to study non-linear phenomena.
The plan of my talk is as follows:
1. A brief introduction in the energy spectrum of electrons in graphene. «Massless Dirac fermions».
2. Nonlinear transport and optical effects. Phenomenology based on the symmetry.
3. Microscopic models: dynamic Hall effect, chiral edge photocurrents, photogalvanic effect.
4. Comparison with experiments.
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