Gap-tunable of Tunneling Time in Graphene Magnetic Barrier

TL;DR

This paper investigates how an energy gap in graphene influences tunneling time of Dirac fermions through a magnetic barrier, revealing a tunable relationship with the gap size and a critical point where delay time stabilizes.

Contribution

It introduces a detailed analysis of tunneling time dependence on the energy gap in graphene, providing new insights into gap-tunable tunneling dynamics.

Findings

Group delay time varies significantly with the energy gap.

At a critical energy gap, the delay time approaches unity.

Delay time becomes independent of physical parameters at the critical gap.

Abstract

We study the tunneling time of Dirac fermions in graphene magnetic barrier through an electrostatic potential and a mass term. This latter generates an energy gap in the spectrum and therefore affects the proprieties of tunneling of the system. For clarification, we first start by deriving the eigenspinors solutions of Dirac equation and second connect them to the incident, reflected and transmitted beam waves. This connection allows us to obtain the corresponding phases shifts and consequently compute the group delay time in transmission and reflection. Our numerical results show that the group delay time depends strongly on the energy gap in the tunneling process through single barrier. Moreover, we find that the group approaches unity at some critical value of the energy gap and becomes independent to the strengths of involved physical parameters.