Spectral scrambling in Coulomb-blockade quantum dots
Abstract
Description
We study the fluctuations of an energy level as a function of the number of electrons $m$ added to a Coulomb-blockade quantum dot. A microscopic calculation in the limit of Koopmans' theorem predicts that the standard deviation of these fluctuations behaves as $\sqrt{m}$ in the absence of surface charge but is linear in $m$ when the effect of a surface charge in a finite geometry is included. The microscopic results are compared to a parametric random-matrix approach. We estimate the number of electrons it takes to scramble the spectrum completely in terms of the interaction strength, the dimensionless Thouless conductance, and the symmetry class.
13 pages, RevTex, significantly revised and includes new results
13 pages, RevTex, significantly revised and includes new results