  A theoretical model for tunneling spectroscopy employing tight-binding band
structure, d-wave gap symmetry, group velocity, and tunneling directionality
can exhibit a wide range of characteristics similar to the ones found in
tunneling experiments on high-Tc superconductors. Using a band structure
obtained for optimally-doped Bi_2Sr_2CaCu_2O_8, the model tunneling density of
states produces a good comparison to the point-contact tunneling conductance on
the same material, especially in the gap region, displaying the same sub-gap
shape and conductance peaks asymmetry.

Superconductivity