Ultrafast dynamics of fluctuations in high-temperature superconductors far from equilibrium

L. Perfetti (1) , B. Sciolla (2) , G. Biroli (2) , C. J. van Der Beek (3) , C. Piovera (1) , M. Wolf (4) , T. Kampfrath (5)

1 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory
2 IPHT - Institut de Physique Théorique - UMR CNRS 3681
3 Department of Physics and CMSE
4 JGU - Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University
5 Fachbereich Physik [Freie Univeristät Berlin] | Department of Physics [Freie Univeristät Berlin]

Despite extensive work on high-temperature superconductors, the critical behavior of an incipient condensate has so far been studied exclusively under equilibrium conditions. Here, we excite Bi2Sr2CaCu2O8+d with a femtosecond laser pulse and monitor the subsequent nonequilibrium dynamics of the mid-infrared conductivity. Our data allow us to discriminate temperature regimes where superconductivity is either coherent, fluctuating or vanishingly small. Above the transition temperature Tc, we make the striking observation that the relaxation to equilibrium exhibits power-law dynamics and scaling behavior, both for optimally and underdoped superconductors. Our findings can in part be modeled using time-dependent Ginzburg-Landau theory and provide strong indication of universality in systems far from equilibrium.

Domaines: Physique [physics]

L. Perfetti, B. Sciolla, G. Biroli, C. J. van Der Beek, C. Piovera, et al.. Ultrafast dynamics of fluctuations in high-temperature superconductors far from equilibrium. Physical Review Letters, 2015, 114 (6), pp.067003. ⟨10.1103/PhysRevLett.114.067003⟩. ⟨cea-01188589⟩