Theory of the tunneling spectroscopy of ferromagnetic superconductors

We study tunneling conductance in normal metal-insulator-ferromagnetic superconductor junctions. The tunneling spectra show a clear difference between spin-singlet $s$-wave pairing, spin-triplet opposite spin pairing, and spin-triplet equal spin pairing: These pairings exhibit, respectively, gap structure, double peak structure, and zero-bias peak in the spectra. The obtained result may serve as a tool for determining the pairing symmetry of ferromagnetic superconductors.

Figure 1

(Color online) Normalized tunneling conductance with $Z=10$ for (a) $s$-wave pairing, (b) OSP, and (c) ESP.

Figure 2

(Color online) Normalized tunneling conductance with $Z=1$ for (a) $s$-wave pairing, (b) OSP, and (c) ESP.