Europhys. Lett.
Volume 70, Number 5, June 2005
Page(s) 663 - 669
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 29 April 2005
Europhys. Lett., 70 (5), pp. 663-669 (2005)
DOI: 10.1209/epl/i2005-10028-0

Distribution of conduction channels in nanoscale contacts: Evolution towards the diffusive limit

J. J. Riquelme1, L. de la Vega2, A. Levy Yeyati2, 3, N. Agraït1, 3, A. Martin-Rodero2, 3 and G. Rubio-Bollinger1, 3

1  Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada C-III, Universidad Autónoma de Madrid - E-28049 Madrid, Spain
2  Departamento de Física Teórica de la Materia Condensada C-V Universidad Autónoma de Madrid - E-28049 Madrid, Spain
3  Instituto Universitario de Ciencia de Materiales "Nicolás Cabrera" Universidad Autónoma de Madrid - E-28049 Madrid, Spain

received 25 January 2005; accepted in final form 8 April 2005
published online 29 April 2005

We present an experimental determination of the conduction channel distribution in lead nanoscale contacts with total conductances ranging from 1 to 15 G0, where G0=2e2/h. It is found that even for contacts having a cross section much smaller than the mean free path the distribution tends to be remarkably close to the universal diffusive limit. With the help of theoretical calculations we show that this behavior can be associated with the specific band structure of lead which produces a significant contribution of partially open channels even in the absence of atomic disorder.

73.23.-b - Electronic transport in mesoscopic systems.
73.63.Rt - Nanoscale contacts.
73.40.Jn - Metal-to-metal contacts.

© EDP Sciences 2005