Disordered granular aluminium films: Quantum corrections and resistive peak above the superconducting transition

Abstract

The enigmatic resistive peak observed just prior to the onset of superconductivity, traditionally attributed to quantum corrections from superconducting fluctuations and weak localization, has been extensively studied in conventional films. But what happens in granular aluminium films with tunable disorder? We tackle this question by probing granular aluminium films, revealing how competing quantum effects influence the transport behaviour near the superconducting transition. Through high-precision magnetotransport experiments, we disentangle the contributions of Aslamazov-Larkin and Maki-Thompson fluctuations and demonstrate how strong electron-electron interactions suppress weak localization effects. By analyzing the evolution of the modified Larkin parameter alongside dephasing dynamics, we identify the dominant scattering mechanisms in the regime where ln(T/T_c) < 1. Our findings provide new insights into the crossover from fluctuation-driven to disorder-dominated transport, bridging the understanding between crystalline superconductors and their amorphous granular counterparts.