Galda Alexey, Mel'nikov A S, Vinokur V M
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
1] Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105, Russia [2] Lobachevsky State University of Nizhny Novgorod, 23 Prospekt Gagarina, 603950, Nizhny Novgorod, Russia.
Sci Rep. 2015 Feb 9;5:8315. doi: 10.1038/srep08315.
Superconducting fluctuations have proved to be an irreplaceable source of information about microscopic and macroscopic material parameters that could be inferred from the experiment. According to common wisdom, the effect of thermodynamic fluctuations in the vicinity of the superconducting transition temperature, Tc, is to round off all of the sharp corners and discontinuities, which otherwise would have been expected to occur at Tc. Here we report the current spikes due to radiation-induced resonant tunneling of fluctuation Cooper pairs between two superconductors which grow even sharper and more pronounced upon approach to Tc. This striking effect offers an unprecedented tool for direct measurements of fluctuation Cooper pair lifetime, which is key to our understanding of the fluctuation regime, most notably to nature of the pseudogap state in high-temperature superconductors. Our finding marks a radical departure from the conventional view of superconducting fluctuations as a blurring and rounding phenomenon.
超导涨落已被证明是有关微观和宏观材料参数的不可替代的信息来源，这些参数可从实验中推断出来。根据普遍观点，在超导转变温度Tc附近，热力学涨落的作用是使所有尖锐的角和不连续性变得平滑，否则这些情况预计会在Tc处出现。在此，我们报告了由于辐射诱导的两个超导体之间的涨落库珀对的共振隧穿而产生的电流尖峰，当接近Tc时，这些尖峰变得更加尖锐和明显。这种显著的效应为直接测量涨落库珀对寿命提供了前所未有的工具，而涨落库珀对寿命是我们理解涨落区域的关键，对于理解高温超导体中的赝能隙态的性质尤为重要。我们的发现与将超导涨落视为模糊和平滑现象的传统观点有根本的不同。
