We study the tunneling spectra for superconductor-insulator-normal metal (S-I-N) tunnel junctions with an s -wave or a d -wave superconductor within the weak-coupling model. We deduce the temperature behavior of tunneling conductance and their peak positions as well as of the zero-bias conductance. The results obtained allow us to discriminate among the two singlet spin states.
Time-reversal symmetry breaking and spontaneous currents ins-wave/normal-metal/d-wave superconductor sandwiches