Oxide thin film based inverse superconducting spin switches.

Thin film F/S/F trilayers made of YBa2Cu3O7 (S, YBCO) and La0.7Ca0.3MnO3 (F, LCMO) behave as inverse superconducting spin switches (SSS) as the critical temperature of the superconductor depends on the relative orientation of the magnetization of the F layers in a way that the resistivity is increased in the antiparallel configuration. This is caused by enhanced pair-breaking due to the spin dependent transport of quasiparticles transmitted from the ferromagnetic electrodes into the superconductor. Similar inverse SSS is obtained from exchange biased LCMO/YBCO/Cobalt trilayers with a broad AP field range. Spin diffusion across the superconductor, proximity effect at the F/S interface, stray fields due to domain walls of the ferromagnet and the magnetic anisotropy all play a role.