Nature of the superconducting fluctuations in photoexcited systems
Nature of the superconducting fluctuations in photoexcited systems
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光激发系统中超导涨落的本质
DOI：
10.1103/physrevb.100.104521
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发表时间：
2019
影响因子：
3.7
通讯作者：
and Shintaro Hoshino
中科院分区：
文献类型：
--
作者：
Ryuta Iwazaki;Naoto Tsuji;and Shintaro Hoshino
基于含时Ginzburg-Landau方法，研究了超导临界温度以上与超导涨落有关的光激发态。激发态由电场脉冲产生，由弱二次外场探测，用模拟泵浦-探测光谱学实验的线性响应理论处理。这种行为基本上由两个弛豫率控制：一个与从临界点测量的温度成正比，另一个与泵浦脉冲的激发强度成正比。激发态在很长一段时间内指数逼近平衡态，而在中间时间域中，即使系统远离临界点，我们也发现了不同指数的幂衰减或对数衰减。这被解释为在激发情况下，平衡的临界点扩展到有限区域。从各个维度系统地研究了泵浦电流和探测电流的参数依赖关系。
The photoexcited state associated with superconducting fluctuations above the superconducting critical temperatureis studied based on the time-dependent Ginzburg-Landau approach. The excited state is created by an electric-field pulse and is probed by a weak secondary external field, which is treated by the linear response theory mimicking pump-probe spectroscopy experiments. The behavior is basically controlled by two relaxation rates: one isproportional to the temperature measured from the critical point, and the other isproportional to the excitation intensity of the pump pulse. The excited state approaches the equilibrium state exponentially in a long time, while in the intermediate-time domain we find a power-law or logarithmic decay with different exponents forand, even though the system is located away from the critical point. This is interpreted as the critical point in equilibrium being extended to a finite region in the excited situation. The parameter dependences on both the pump and probe currents are also systematically studied in all dimensions.