Ultrafast dynamics of fluctuations in high-temperature superconductors far from equilibrium.
Ultrafast dynamics of fluctuations in high-temperature superconductors far from equilibrium.
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DOI：
10.1103/physrevlett.114.067003
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发表时间：
2014-07
影响因子：
8.6
通讯作者：
L. Perfetti;Bruno Sciolla;Giulio Biroli;C. J. V. D. Beek;C. Piovera;Martin Wolf;T. Kampfrath
中科院分区：
文献类型：
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作者：
L. Perfetti;Bruno Sciolla;Giulio Biroli;C. J. V. D. Beek;C. Piovera;Martin Wolf;T. Kampfrath
尽管在高温超导体上进行了大量的工作，但到目前为止，初始凝聚态的临界行为仅在平衡条件下进行了研究。在这里，我们用飞秒激光脉冲激发Bi（2）Sr（2）CaCu（2）O（8+δ），并监测随后的中红外电导率的非平衡动力学。我们的数据使我们能够区分超导性是相干的，波动的或消失的小的温度制度。在转变温度T（c）以上，我们发现了一个惊人的现象，即对于最佳和欠掺杂超导体，弛豫到平衡态的过程都表现出幂律动力学和标度行为。我们的研究结果可以部分地使用时间相关的金斯堡-朗道理论来建模，并且它们提供了远离平衡的系统的普遍性的强有力的指示。
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.