Evidence of a photoinduced non-thermal superconducting-to-normal-state phase transition in overdoped Y-Bi2212

Here we report extensive ultrafast time-resolved reflectivity experiments on overdoped Y-Bi2212 single crystals (Tc=78 K) aimed to clarify the nature of the superconducting-to-normal-state photoinduced phase transition. The experimental data show the lack of the quasiparticles decay time divergence at the fluence required to induce this phase transition, in contrast to the thermally-driven phase transition observed at Tc and at variance with recently reported photoinduced charge-density-wave and spin-density-wave to metal phase transitions. Our data demonstrate the non-thermal character of the superconducting-to-normal-state photoinduced phase transition. The data have been analyzed using an ad-hoc developed timedependent Rothwarf-Taylor model, opening the question on the order of this non-equilibrium phase transition.