Modeling of Tunneling Spectroscopy in High-Tc Superconductors

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.