  Hybrid Superconductor/Ferromagnet structures have been investigated recently
to address the interplay between ferromagnetism and superconductivity. They
also open up new routes for the investigation of out of equilibrium
superconductivity. Here, we show how it is possible for out of equilibrium
excitations produced in a superconducting thin film (S) to be localized in a
ferromagnetic trap (F). Specifically, a ferromagnetic nano-volume in good
contact with S represents a potential well for the quasiparticles (QPs) at the
gap edge. As the superconducting proximity effect is highly suppressed in F,
QPs get efficiently trapped and they share their energy with the free electrons
in the trap. The electronic temperature Te in the trap can be increased by up
to 60% from the bath temperature at 320 mK as measured by tunneling
spectroscopy using a second junction.
