Universal conductance reduction in a quantum wire
arXiv:cond-mat/0303347 · doi:10.1209/epl/i2004-10285-3
Abstract
Even a single point defect in a quantum wire causes a conductance reduction. In this paper we prove (without any approximations) that for any point impurity this conductance reduction in all the sub-bands is exactly 2e^2/h. Moreover, it is shown that in the case of a surface defect, not only is the conductance minimum independent of the defect characteristics, but the transmission matrix also converges to universal (defect-independent) values. We also discuss particle confinement between two arbitrarily weak point defects.
4 pages, 4 figures (Revtex)