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Transport in graphene exposed to a strong electromagnetic field

Event Details

Event Dates: 

Thursday, October 31, 2013 - 6:00am

Seminar Location: 

  • Duane Physics Room D142

Speaker Name(s): 

Sergey Syzranov

Speaker Affiliation(s): 

University of Colorado Boulder
Seminar Type/Subject

Scientific Seminar Type: 

  • Condensed Matter Seminar

Event Details & Abstract: 

This talk is devoted to the quasiparticle dynamics in graphene exposed to a linearly-polarised electromagnetic wave of very large intensity. I will demonstrate that low-energy transport in such system can be described by an effective time-independent Hamiltonian, characterised by multiple Dirac points in the first Brillouin zone. Around each Dirac point the spectrum is anisotropic: the velocity along the polarisation of the radiation significantly exceeds the velocity in the perpendicular direction. Moreover, in some of the points the transverse velocity oscillates as a function of the radiation intensity. These features of the spectrum manifest themselves in transport phenomena in irradiated graphene samples. For instance, the conductance of a graphene p-n junction in the regime of strong irradiation depends on the polarisation as $G(\theta)\propto|\sin\theta|^{3/2}$, where $\theta$ is the angle between the polarisation and the p-n interface, and oscillates as a function of the radiation intensity.