title: Mesoscopic to universal crossover of the transmission phase of multilevel quantum dots.
abstract: Transmission phase alpha measurements of many-electron quantum dots (small mean level spacing delta) revealed universal phase lapses by pi between consecutive resonances. In contrast, for dots with only a few electrons (large delta), the appearance or not of a phase lapse depends on the dot parameters. We show that a model of a multilevel quantum dot with local Coulomb interactions and arbitrary level-lead couplings reproduces the generic features of the observed behavior. The universal behavior of alpha for small delta follows from Fano-type antiresonances of the renormalized single-particle levels.
authors.affiliation: Institut für Theoretische Physik, Universität Göttingen, 37077 Göttingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Karrasch
authors.forename: T
authors.initials: T
authors.lastname: Hecht
authors.forename: A
authors.initials: A
authors.lastname: Weichselbaum
authors.forename: Y
authors.initials: Y
authors.lastname: Oreg
authors.forename: J
authors.initials: J
authors.lastname: von Delft
authors.forename: V
authors.initials: V
authors.lastname: Meden