Effect of strain on doped graphene-based N/I/S junction with d-wave superconductivity

We investigate the effect of tensional strain on tunneling conductance in graphene-based normal/insulator/superconductor junction taking into account the anisotropic (d-wave asymmetry) superconductor pairing potential. By applying strain in the zigzag direction to graphene sheet, the highly asymmetric velocity of massless Dirac fermions can be provided. To study the conductance behavior based on Blonder-Thinkham-Klapwijk formalism in the d-wave pair coupling case, we must restrict ourselves to the large Fermi energy in the superconductor region, so that the incident angle of quasiparticles of superconductor region can be possible to calculate exactly in terms of modified wavevectors, k(x) and k(y). In particular, investigation of the effect of Fermi energy mismatch in interface shows that it (E-Fs + U-o) causes a reduction in conductance of structure only in the strain direction. In addition, we illustrate how d-type of pairing asymmetry affects the tunneling conductance in quite different behaviors in parallel and perpendicular directions of strain. (C) 2013 Elsevier Ltd. All rights reserved.