Universal conductance reduction in a quantum wire

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

Corresponding author: erel@yosh.ac.il

Received: 29 July 2004
Accepted: 19 October 2004

Abstract

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 . 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.