Conductance in normal metal/insulator/ferromagnetic superconductor tunnel junctions

In this paper, the superconducting order parameter and the energy spectrum of the Bogoliubov excitations are obtained from the Bogoliubov-de Gennes equation for a ferromagnetic superconductor (FS). In the framework of the Blonder-Tinkham-Klapwijk model, we present the differential conductance of the normal metal/insulator/FS junctions. It is shown that the exchange energy h in the FS can lead to the Zeeman splitting of the conductance peaks and the energy difference between the two splitting peaks is equal to 2h. The observation of such Zeeman splitting in the conductance spectrum can be taken as evidence for the coexistence between superconductivity and ferromagnetism.