Oscillating from "0" to "π" State in Ferromagnet Induced by Superconducting Proximity Effect

This paper extened the BTK theory and the Nambu spinor Green's function approach to study the proximity effects in ferromagnet/superconductor junctions.We calculate the induced superconducting order parameter and density of states(DOS).It is found that the induced density of states in the F side displays a damped oscillating from "0" state to "π" state in period 2 π ξFwith increasing the distance from the interface,which corresponds just to the reversion of the superconducting order parameter from positive to negative.