Josephson current versus potential strength of the interface in ferromagnetic superconductors

Based on the scattering theory, we calculate the Josephson current in a junction between two ferromagnetic super-conductors as a function of the interface potential z. We consider the ferromagnetic superconductor （FS） in three different Cooper pairing states： spin singlet s-wave pairing （SWP） state, spin triplet opposite spin pairing （OSP） state, and spin triplet equal spin pairing （ESP） state. We find that the critical Josephson current as a function of z shows clear differences among the SWP, OSP, and ESP states. The obtained results can be used as a useful tool for determining the pair symmetry of the ferromagnetic superconductors.

Tunneling Conductance in a Normal Metal/Ferromagnetic Superconductor Nano-Junction at a Finite Temperature

In this study, we investigate the tunneling conductance at a finite temperature in a normal metal/ferromagnetic superconductor nano-junction where the ferromagnetic superconductor （FS） is in three different cooper pairing states： spin singlet s-wave pairing （SWP）, spin triplet opposite spin pairing （OSP）, and spin triplet equal spin pairing （ESP） while including Fermi wave mismatch （FWM） and effective mass mismatch （EMM） in two sides of the nano-junction. We find that the conductance shows clearly different behaviors all depending on the symmetries of cooper pairing in a manner that the conductance spectra shows a gap-like structure, two interior dips structure and zero bias peak for SWP, OSP, and ESP, respectively. Also, the effective FS gap （Δeff） is a linear and decreasing function of exchange field. The slope of （Δeff） versus exchange field for OSP is twice the SWP. Thus, we can determine the spin polarization of N/FS nano-junction based on the dependence of （Δeff） to exchange field.

Zero-Bias Conductance versus Potential Strength of Interface in Ferromagnetic Superconductors

We study zero-bias conductance(ZBC)spectra of a normal-metal/insulator/singlet(and triplet)ferromagnetic superconductor as a function of potential strength of interface in the Blonder-Tinkham Klapwijk(BTK)theory framework.We consider possible pairing states including spin singlet s-wave pairing(SWP),spin triplet opposite spin pairing(OSP)and spin triplet equal spin pairing(ESP).It is found that ZBC as a function of potential strength of interface shows a clear difference between SWP,OSP and ESP states.These results may serve as a useful tool for discriminating pairing states in ferromagnetic superconductors.