Note on Hartman effect in gapped graphene

In this manuscript the effect of an opening gap on the dwell time corresponding to the electronic tunneling in graphene is explored. It is shown that tunneling time of quasiparticles in passing through junctions of gapped graphene as well as pure flakes is not independent of the barrier thickness and therefore Hartman effect is not observed due to tunneling of relativistic electrons with a finite effective mass in graphene. The numerical results also reveal that the traversal time in gapped graphene is equal to the traversal time in absence of the barrier for a broad range of incident energy. It is also found that the origin of the problem of Hartman effect could be explained in terms of an average-constant behavior of the probability density of the electronic wave under the barrier.