Photoinduced melting of superconductivity in the high-Tc superconductor   La2-xSrxCuO4 probed by time-resolved optical and THz techniques
  Dynamics of depletion and recovery of superconducting state in La2-xSrxCuO_4 thin films is investigated utilizing optical pump-probe and optical pump - THz probe techniques as a function of temperature and excitation fluence. The absorbed energy density required to suppress superconductivity is found to be about 8 times higher than the thermodynamically determined condensation energy density and nearly temperature independent between 4 and 25 K. These findings indicate that during the time when superconducting state suppression takes place (~0.7 ps), a large part (nearly 90%) of the energy is transferred to the phonons with energy lower than twice the maximum value of of the SC gap and only 10% is spent on Cooper pair breaking. 
M. Beyer, M. Beck, D. St\"adter, H. Sch\"afer, V.V. Kabanov, G.   Logvenov, I. Bozovic, G. Koren, and J. Demsar
cond-mat.supr-con cond-mat.str-el