Melting the Superconducting State in the Electron Doped Cuprate   Pr$_{1.85}% $Ce$_{0.15}$CuO$_{4-\delta}$ with Intense near-infrared and   Terahertz Pulses
  We studied the superconducting (SC) state depletion process in an electron doped cuprate Pr$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ by pumping with near-infrared (NIR) and narrow-band THz pulses. When pumping with THz pulses tuned just above the SC gap, we find the absorbed energy density required to deplete superconductivity, $A_{dep}$, matches the thermodynamic condensation energy. Contrary, by NIR pumping $A_{dep}$ is an order of magnitude higher, despite the fact that the SC gap is much smaller than the energy of relevant bosonic excitations. The result implies that only a small subset of bosons contribute to pairing. 
M. Beck, M. Klammer, I. Rousseau, M. Obergfell, P. Leiderer, M. Helm,   V.V. Kabanov, I. Diamant, A. Rabinowicz, Y. Dagan, a...
cond-mat.supr-con cond-mat.str-el