Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

We investigate the intraband nonlinear dynamics in doped bilayer graphene in the
presence of strong, linearly-polarized, in-plane terahertz fields. We perform degenerate
pump-probe experiments with 3.4 THz fields on doped bilayer graphene at low temper-
ature (12 K) and find that when the pump is co-polarized with the probe beam, the
differential pump-probe signal is almost double that found in the cross-polarized case.
We show that the origin of this pump-induced anisotropy is the difference in the aver-
age electron effective mass in the probe direction when carriers are displaced in k-space
by the pump either parallel or perpendicular to the direction of the probe polarization.
We model the system using both a simple semiclassical model and a Boltzmann equa-
tion simulation of the electron dynamics with phenomenological scattering and find
good qualitative agreement with experimental results.