Dwell time in one-dimensional graphene asymmetrical barrier

The authors have investigated theoretically the dwell time of Dirac fermions tunneling through electrostatic square barrier in monolayer graphene, including asymmetrical and symmetrical potential barriers. It is found that the incident angle determines the critical incident energy. When the incident energy is larger than the critical incident energy, the dwell time saturate with the increase of the barrier thickness. But when the incident energy is smaller than the critical incident energy, the dwell time oscillates with the increase of the barrier thickness. The behaviors of oscillation and saturation of the dwell time are related with the transmission probability. These results may be helpful for the basic physics and potential application of graphene based electronic devices.