Quantized Josephson phase battery

A ferromagnetic Josephson junction with a spin-flipper (magnetic impurity) sandwiched in-between acts as a phase battery that can store quantized amounts of superconducting phase difference \varphi₀ in the ground state of the junction. Moreover, for such \varphi₀ -Josephson junction, anomalous Josephson current appears at zero phase difference. We study the properties of this quantum spin-flip scattering-induced anomalous Josephson current, especially its tunability via misorientation angle between two ferromagnets.