Abstract-Ultrafast terahertz response of multilayer graphene in the nonperturbative regime

P. Bowlan, E. Martinez-Moreno, K. Reimann, T. Elsaesser, and M. Woerner
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany

 Published 27 January 2014; received 18 June 2013

The nonlinear dynamics of electrons in multilayer epitaxial graphene is investigated by time-resolved terahertz (THz) spectroscopy in a regime where the interaction of electrons with the external field dominates over scattering processes. The predominantly coherent electron response to the THz field involves both intra- and interband currents, leading to coherently driven interband transitions of carriers and to the generation of higher harmonics of the THz carrier frequency. The overall behavior of the graphene layers is always absorptive, even after generation of an initial electron-hole distribution by femtosecond midinfrared excitation. The results are in agreement with theoretical calculations of the nonperturbative THz response.

©2014 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevB.89.041408

DOI:

10.1103/PhysRevB.89.041408

PACS:

72.80.Vp, 72.20.Ht, 73.22.Pr, 78.47.J-