Hartman effect at merging point in graphene under uniaxial strain

Highlights: • We used the universal Hamiltonian for description of graphene under uniaxial strain. • The numerical results of the tunneling time for several values of δ were presented. • The effect of barrier's height, energy … on the traversal time was considered. • The merging parameter was shown to be important character in the Hartman effect. • Hartman effect was not observed for $\delta =0$ and $\delta <0$ in the case of normal incidence. The dwell time corresponding to the Klein tunneling of Dirac fermions confined in single-layer graphene in the presence of uniaxial strain was investigated. The numerical results of the tunneling time and the transmission probability for several values of the merging parameter were presented. The effect of barrier's height/length, energy, incident angle and merging parameter on the traversal time was considered. Results showed that the merging parameter and the angle of the incidence were important characters in the existence of the Hartman effect, and therefore Hartman effect was not observed at tunneling of Dirac fermions with different values of merging parameter for $\delta =0$ and $\delta <0$ for normal incident. In the case of $\delta >0$ are equivalent to the gapped graphene under uniaxial strain at the merging point, tunneling time was independent on the barrier thickness.