Quantum point contact conductance in normal metal/insulator/ metal/dx2−y2+idxy mixed wave superconductor junctions

The tunneling conductance in a normal metal/insulator/metal/dx2−y2+idxy mixed wave superconductor (N/I/N/dx2−y2+idxy) junction is calculated, where the N/I/N region is a quantum wire. It is found in the single-mode case that the magnitude of the tunneling conductance near zero voltage is enhanced due to the Andreev bound state by quasiparticles with perpendicular and horizontal injection, and the zero-bias conductance varies with LL (LL is the distance from insulating layer to the interface of N/dx2−y2+idxy mixed wave superconductor). Splitting of the zero-bias conductance peak appears in the quantum point contact tunneling spectra for an N/I/N/dx2−y2+idxy junction, and several subgap peaks can split at the same time. On increasing both LL and the magnitude ratio of the two components for the dx2−y2+idxy mixed wave, the subgap resonances exhibit an alternately high and low behavior inside the energy gap. These results are different from those in d-wave and p-wave superconductor junctions.