▎ 摘　　要

The tunneling conductance in a NG/SG graphene junction in which the graphene was grown on a SiC substrate is simulated. The carriers in the normal graphene (NG) and the superconducting graphene (SG) are treated as massive relativistic particles. It is assumed that the Fermi energy in the NG and SG are E-FN similar to 400 meV and E-FS similar to 400 meV + U. respectively. Here U is the electrostatic potential from the superconducting gate electrode. It is seen that the Klein tunneling disappears in the case where a gap exist in the energy spectrum. As U -> infinity, the zero bias normalized conductance becomes persistent at a minimal value of G/G(0) similar to 1.2. The normalized conductance G/G(0) is found to depend linearly on U with constant slope of alpha = 2/(E-FN - mv(F)(2)) similar to 7.4, where 2mv(F)(2) is the size of the gap A opening up in the energy spectrum of the graphene grown on the SiC substrate. it is round that G1/G(0) congruent to 2 + alpha U for potentials in the range -270 meV < U < 0 meV and G = 0 for potentials U < -270 meV. As alpha -> infinity, the conductance for eV = Delta (V is the bias voltage placed across the NG/SG junction) can be approximated by a unit step function G(eV = Delta, U)/G(0) similar to 2 Theta(U). This last behavior indicates that a NG/SG junction made with gapped graphene could be used as a nano switch having excellent characteristics. (C) 2009 Elsevier B.V. All rights reserved.