Experimental evidence and consequences of rare events in quantum tunneling
Institut de Physique et Chimie des Matériaux de Strasbourg (UMR 7504
CNRS - Université Louis Pasteur.) , 23 rue du Loess, 67037 Strasbourg Cedex, France
Published online: 15 January 2000
Tiny spatial fluctuations of tunnel barrier parameters are shown to have dramatic consequences on the statistical properties of quantum tunneling. A direct experimental evidence is provided that the tunnel current through metal-oxide junctions, imaged at a nanometric scale, exhibits broad statistical distributions extending over more than 4 orders of magnitude. Striking effects of broad current distributions are shown: the total tunnel transmission is dominated by few highly transmitting sites and the typical current density varies strongly with the size of the junction. Moreover, self-averaging of the tunnel current fluctuations occurs only for unexpectedly large junction areas.
PACS: 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 73.40.Gk – Tunneling / 73.40.Rw – Metal-insulator-metal structures
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000