Suppression of Superconductivity in YBCO/LCMO Superlattices

摘要

The competition of superconductivity and magnetism in superlattices composedof alternating YBa$_2$Cu$_3$O$_{7-d}$ and La$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thinfilms is investigated using low-energy optical spectroscopy. The thickness ofthe superconducting YBCO layers is varied from 30 nm to 20 nm while thethickness of the magnetic LCMO layers is kept constant at 20 nm. We clearlyobserve that the superconducting condensate density in the superconductingstate of superlattice is drastically reduced by the magnetic subsystem whichmay be connected with proximity effects that distort the gap symmetry and thussuppress superconductivity.