Europhys. Lett.
Volume 68, Number 6, December 2004
Page(s) 860 - 866
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 17 November 2004
Europhys. Lett., 68 (6), pp. 860-866 (2004)
DOI: 10.1209/epl/i2004-10285-3

Universal conductance reduction in a quantum wire

E. Granot

Department of Electrical and Electronics Engineering, College of Judea and Samaria Ariel 44837, Israel

received 29 July 2004; accepted in final form 19 October 2004
published online 17 November 2004

A single impurity in a quantum wire exhibits a conductance reduction. In this paper we prove (without any approximations) that for any point impurity this conduction reduction in all the subbands is exactly 2e2/h. It is also shown that in the case of a surface defect, not only are the conductance minima independent of the defect characteristics, but also the transmission matrix converges to universal values. We use these calculations to discuss particle confinement between two arbitrarily weak point defects.

72.10.Fk - Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect).
03.65.Nk - Scattering theory.
73.21.Hb - Quantum wires.

© EDP Sciences 2004