Coherent photocurrent control in graphene in a magnetic field

We consider theoretically the coherent optical control of a graphene sheet in a perpendicular magnetic field. When a two-color optical beam is applied, rotating photocurrents of electrons and holes are generated through interference between one-and two-photon processes which place electrons or holes in adjacent Landau levels. These oppositely rotating currents contain multiple frequency components in the terahertz range due to the unequal Landau level spacing combined with the finite pulse bandwidths. The overall current oscillates in a direction determined by the pulse polarization, and the phase of oscillation can be tuned through a relative phase parameter of the pulses. The magnitude of the current is predicted to be comparable to that already detected in the absence of a magnetic field, so these effects should be observable.