Ageing in granular aluminium insulating thin films

TL;DR

This study investigates how conductance relaxations in granular aluminium insulating thin films depend on the system's age, revealing age-dependent dynamics similar to glassy systems, and provides new insights for theoretical modeling.

Contribution

It introduces new electrical measurements showing age dependence in conductance relaxations, offering fresh experimental data to refine theoretical models of disordered insulators.

Findings

Age affects conductance relaxation behavior.

Relaxation dynamics resemble those in glassy systems.

Results differ from previous studies with other protocols.

Abstract

We present a new set of electrical field effect measurements on granular aluminium insulating thin films. We have explored how the conductance relaxations induced by gate voltage changes depend on the age of the system, namely the time elapsed since its quench at low temperature. A clear age dependence of the relaxations is seen, qualitatively similar to ageing effects seen in other well studied glassy systems such as spin glasses or polymers. We explain how our results differ from the previous ones obtained with different protocols in indium oxide and granular aluminium thin films. Our experimental findings bring new information on the dynamics of the system and put new constraints on the theoretical models that may explain slow conductance relaxations in disordered insulators.