Tunneling time and transmission properties in strained graphene with a time-oscillating potential

Abstract

We investigate the transport properties, the group delay time and the Hartman effect through the graphene electrostatic barrier with a time-dependent oscillating potential, under zigzag and armchair strains. In this work, we demonstrated that as the armchair-direction strain is applied, the transmission has a gap for the sidebands, as well as the central band. The transmission gap strongly depends on strain strength and barrier height. We found that the transmission probability can be controlled by adjusting the amplitude of the time-oscillating potential. The transmission probability for the nonzero angle of incidence, unlike the zero angles of incidence, depends on the sign of n for the nth sideband. Also, the group delay time is sensitive to the order of the sidebands. The barrier width is very important parameter in controlling the group delay time of various sidebands. Remarkably, the Hartman effect, for the armchair strain, in contrast to the zigzag direction strain, can be observed at the zero angles of incidence, for both the sidebands and the central band.