0-π transitions in mesoscopic Josephson junctions with magnetic impurity interlayers

The magnetic impurity effect on the Josephson current through mesoscopic tunnel junctions is investigated by numerically solving the Bogoliubov-de Gennes equations self-consistently. It is found that the presence of magnetic impurities in the middle layers significantly affects the current flowing across the junctions with d-wave superconductors. A 0 or π state for the current-phase relation with a period of 2π can be realized when the thickness of middle magnetic impurity layers is varied. Moreover, the 0-π or π-0 transitions are demonstrated with increasing the temperature for Josephson junctions with specific interlayer thicknesses.