Low-Temperature Resistance Noise Spectroscopy as a Probe of the Superconducting Transition in Underdoped La_(2-x)Sr_xCuO_4

摘要

We report the resistance noise spectroscopy technique and its applications in detecting the nature of high-temperature superconducting transition in cuprates. In underdoped La_(2_x)Sr_xCuO_4 thick films, in which interlayer coupling is relatively weak and thus the system is effectively two-dimensional, resistance noise spectroscopy shows the first experimental evidence of intrinsic correlated dynamics near the superconducting transition of the Berezinskii-Kosterlitz-Thouless type. In particular, resistance fluctuations in the low-temperature ordered phase are correlated, slow and nonergodic, i.e., the system exhibits properties that cannot be fully detected in any reasonable experimental time frame.