Spin-polarized quasiparticle transport in ferromagnet–d-wave-superconductor junctions with a{110}interface

Abstract

Within a scattering framework, a theoretical study is presented for the spin-polarized quasiparticle transport in ferromagnet–$d$-wave-superconductor junctions with $\{110\}$ interface. We find that the subgap conductance behaviors are qualitatively different from a nonmagnetic case, due to the modification of Andreev reflection by the exchange field in the ferromagnet, and can also be significantly different from those of a ferromagnet–$s$-wave junction because of the sign change of the d-wave order parameter along the $\{110\}$ direction of the crystal. For a ballistic ferromagnet–$d$-wave-superconductor junction, a zero-bias conductance minimum is achieved. In addition, a conductance maximum at finite bias can also be evolved by interfacial scattering. For a normal-metal–ferromagnet–$d$-wave-superconductor junction, conductance resonances are predicted.