2008/04/30 by Claudio Giannetti, Giacomo Coslovich, Federico Cilento +8 · 58 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Advanced Chemical Physics Studies #Atomic physics #Condensed matter physics #Discontinuity (linguistics) #Fluence #High-pressure geophysics and materials #Laser #Materials science #Mathematical analysis #Mathematics #Phase (matter) #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quasiparticle #Superconductivity #Ultrashort pulse #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.79.224502
published in Physical Review B 79(22) (American Physical Society) · Manuscript: 8 pages, 4 figures Supporting material: 2 pages
arxiv created 2008/04/30 · openalex publication_date 2009/06/03 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report the experimental evidence of an abrupt transition of the ultrafast electronic response of underdoped superconducting Bi2Sr2CaCu2O_8+\ensuremathδ, under the impulsive photoinjection of a high density of excitations, using ultrashort laser pulses and avoiding significant laser heating. The direct proof of this process is the discontinuity of the transient optical electronic response, observed at a critical fluence of \ensuremathΦth\ensuremath≃70 \ensuremathμJ/cm2. Below this threshold, the recovery dynamics is described by the Rothwarf-Taylor equations, whereas, above the critical intensity, a fast electronic response is superimposed to a slower dynamics related to the superconductivity recovery. We discuss our experimental findings within the frame of the available models for nonequilibrium superconductivity, i.e., the Teff and \ensuremathμeff models. The measured critical fluence is compatible with a first-order photoinduced phase transition triggered by the impulsive shift of the chemical potential. The measured value, significantly in excess of the condensation energy, indicates that, close to the threshold, the largest amount of energy is delivered to phonons or to other gap-energy excitations strongly coupled to Cooper pairs.