Noise Spectroscopy Investigation of Interplay Between Quantum Interference Effects and Superconductivity in Infinite Layer Cuprates

The interplay between quantum interference effects and superconductivity has been investigated in infinite layer Sr1-xLaxCuO2 +/-delta thin films by using a combination of standard dc electric transport measurements and noise characterization. A marked resistivity upturn at a temperature of 110 K has been observed in underdoped samples, which also showed a superconductive transition at about 25 K. The resistivity behavior has been attributed to weak localization and has been investigated by detailed low-frequency voltage-spectral density measurements. In particular, peculiar linear dependence of the 1/f noise on the bias current is found in the weak-localization regime, whereas the usual quadratic dependence of the 1/f component occurs in the superconducting and metallic regions.