Ultrafast dynamics of fluctuations in high-temperature superconductors far from equilibrium.
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 Bi(2)Sr(2)CaCu(2)O(8+δ) with a femtosecond laser pulse and monitor the subsequent nonequilibrium dynamics of the midinfrared conductivity. Our data allow us to discriminate temperature regimes where superconductivity is either coherent, fluctuating or vanishingly small. Above the transition temperature T(c), 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 they provide strong indication of universality in systems far from equilibrium.
Laboratoire des Solides Irradiés, Ecole polytechnique, 91128 Palaiseau cedex, France.
L
L
Perfetti
Departement of Theoretical Physics, Ecole de Physique University of Geneva 24, Quai Ernest Ansermet 1211 Genéve, Switzerland.
B
B
Sciolla
Institut de Physique Théorique CEA, (CNRS URA 2306), 91191 Gif-sur-Yvette, France.
G
G
Biroli
Laboratoire des Solides Irradiés, Ecole polytechnique, 91128 Palaiseau cedex, France.
C J
CJ
van der Beek
Laboratoire des Solides Irradiés, Ecole polytechnique, 91128 Palaiseau cedex, France.
C
C
Piovera
Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany.
M
M
Wolf
Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany.
T
T
Kampfrath