Charge pumping due to triplet vector chirality in ferromagnet/triplet superconductor junctions

We investigate charge pumping in ferromagnet/triplet superconductor junctions where the magnetization of the ferromagnet is inhomogeneous and dynamical. It is shown that charge current is pumped due to the coupling of the localized spins with triplet vector chirality, vector chirality formed by the triplet vector of Cooper pairing. Physical mechanism of the charge pumping is also discussed.

Figure 1

Schematic of the model. Pumped charge current $j_{c,x}(\mathbf{x},t)$ and the pumped spin current $j_{s,y}^z(\mathbf{x},t)\propto {\nabla }_y{\dot{\mathbf{S}}}^z(\mathbf{x},t)$ for helical $p$-wave superconductivity [Eq. (18)].

Figure 2

Mechanism of the charge pumping. The dynamics of the localized spins is transferred to the triplet Cooper pairing via the exchange coupling. The charge pumping occurs by the dynamics of the Cooper pair with charge $-2e$.