We study the effects of trigonal warping and electric field on the Zitterbewegung of low-energy electrons in bilayer graphene. A time-dependent average velocity of electrons is calculated by using Gaussian wave packets. The Zitterbewegung of electric current shows a transient behavior. The anisotropy of the eigenspectrum due to the trigonal warping distortion breaks the valley symmetry to induce valley-polarized Zitterbewegungs of electric current. An external electric field, applied perpendicular to the layer, opens a band gap and makes the group velocities of electrons at conduction and valence bands slower. Using this feature, we demonstrate that the decay time of the transient Zitterbewegung can be made longer by the electric field. Combining these effects, it is expected that valley-polarized Zitterbewegungs of electric current with longer decay time, which eventually become two valley-polarized constant currents at large times, can exist in a biased bilayer graphene with trigonal warping.

• Received 7 February 2013

DOI:https://doi.org/10.1103/PhysRevB.87.115438