Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 4: CE: Quantum Impurities, Kondo Physics
TT 4.1: Vortrag
Montag, 22. März 2010, 10:15–10:30, H21
Kondo physics in chaotic and regular mesoscopic systems — •Rainer Bedrich1, Sebastien Burdin2, and Martina Hentschel1 — 1Max Planck Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden, Germany — 2Condensed Matter Theory Group, CPMOH, UMR 5798, Université de Bordeaux I, 33405 Talence, France
We study the mesoscopic Kondo box, consisting of a quantum spin 1/2 interacting with an electronic bath as can be realized by a magnetic impurity coupled to electrons on a quantum dot using a mean-field approach for the Kondo interaction. Its numerical efficiency allows us to analyze the Kondo temperature, the local magnetic susceptibility, and the conductance statistics for a large number of samples as a function of the temperature, the Kondo coupling, and the number of electrons on the dot. Here, in contrast to the Kondo effect occurring in a bulk material, the metallic host is characterized by a finite mean level spacing, generating deviations from the universal behavior. We contrast the behavior of chaotic systems, described within the random matrix theory, to that of regular systems, e.g. rectangular quantum dots. Besides the system geometry we find that the boundary of the dot affects the physical properties in a significant way.