Anomalous electric-field effect and glassy behaviour in granular aluminium thin films: electron glass?
LEPES-CNRS, BP 166, 38042 Grenoble Cedex 9, France
Corresponding author: a email@example.com
Revised: 26 March 2007
Published online: 27 April 2007
We present a study of non-equilibrium phenomena observed in the electrical conductance of insulating granular aluminium thin films. An anomalous field effect and its slow relaxation are studied in some detail. The phenomenology is very similar to the one already observed in indium oxide. The origin of the phenomena is discussed. In granular systems, the present experiments can naturally be interpreted along two different lines. One relies on a slow polarisation in the dielectric surrounding the metallic islands. The other one relies on a purely electronic mechanism: the formation of an electron Coulomb glass in the granular metal. More selective experiments and/or quantitative predictions about the Coulomb glass properties are still needed to definitely distinguish between the two scenarios.
PACS: 72.80.Ng – Disordered solids / 61.20.Lc – Time-dependent properties; relaxation / 73.23.Hk – Coulomb blockade; single-electron tunneling
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007