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TT: Fachverband Tiefe Temperaturen

TT 1: TR: Graphene 1 (jointly with MA, HL, and DY)

TT 1.7: Talk

Monday, March 14, 2011, 12:30–12:45, HSZ 03

Tuning the electronic structure of graphene through ac fields: dynamical gaps and polarization effects — •Hernan L. Calvo^1,2, Horacio M. Pastawski¹, Stephan Roche³, and Luis E. F. Foa Torres¹ — ¹Instituto de Fisica Enrique Gaviola and FaMAF UNC, 5000 Cordoba, Argentina — ²Institut für Theoretische Physik A, RWTH Aachen University, D-52056 Aachen, Germany — ³CIN2, CSIC-ICN, Campus UAB, E-08193 Barcelona, Spain

Thanks to its outstanding electrical, mechanical and thermal properties, graphene research is one of the most rapidly advancing fronts ever. Moreover, applications are around the corner, from ballistic transistors to ultracapacitors everything seems possible. Fortunately, there are still many fascinating open problems like the interaction between a laser field and the electrons in graphene. In this work, we discuss this issue within the non-adiabatic regime in terms of both Dirac band and tight-binding models and contrast the obtained results. Notably, we find that the interaction with the field gives rise to back-scattering processes that open dynamical gaps in the electronic structure. The strong dependence of these phenomena on the polarization is emphasized. Our predictions show that these effects should be observable with present laser technology, thereby opening promising prospects for graphene-based opto-electronic devices.