Magnetic-Field-Induced Stabilization of Non-Equilibrium   Superconductivity
  A small magnetic field is found to enhance relaxation processes in a superconductor thus stabilizing superconductivity in non-equilibrium conditions. In a normal-metal (N) - insulator - superconductor (S) tunnel junction, applying a field of the order of 100 \mu T leads to significantly improved cooling of the N island by quasiparticle (QP) tunneling. These findings are attributed to faster QP relaxation within the S electrodes as a result of enhanced QP drain through regions with locally suppressed energy gap due to magnetic vortices in the S leads at some distance from the junction. 
J. T. Peltonen, J. T. Muhonen, M. Meschke, N. B. Kopnin, J. P. Pekola
cond-mat.supr-con cond-mat.mes-hall