Electrical glassy behavior in granular aluminium thin films

Julien Delahaye (1) , Thierry Grenet (1)

1 NEEL - MagSup - Magnétisme et Supraconductivité

We present new results obtained by field effect measurements on insulating granular Al thin films. First, reproducible and stable conductance fluctuations are seen in micron size samples as a function of gate voltage. The anomalous field effect and its slow relaxation already known to exist in macroscopic samples are shown to still exist in small samples and to have no influence on the fluctuations pattern. Secondly, "true" aging is demonstrated, i.e. the anomalous field effect relaxation depends on the time elapsed since the cooling, the longer this time the longer it takes for the system to react to a gate voltage change. Interpretations and implications of these findings are discussed.

Mots clés: Disordered solids; Electrical conductivity; Glass transitions; Time dependent properties--relaxations

Domaines: Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]

Julien Delahaye, Thierry Grenet. Electrical glassy behavior in granular aluminium thin films. Physica B: Condensed Matter, 2009, 404, pp.470-472. ⟨10.1016/j.physb.2008.11.040⟩. ⟨hal-00710725⟩