Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: Correlated Electrons - Poster Session

TT 20.83: Poster

Mittwoch, 28. März 2007, 14:00–17:45, Poster A

Anderson Orthogonality Catastrophe in Mesoscopic Systems — •Georg Röder, Swarnali Bandopadhyay, and Martina Hentschel — Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany

Anderson orthogonality catastrophe (AOC) is an universal many-body response of an electron gas subject to a sudden, localised perturbation. It refers to the vanishing of overlap of the unperturbed and perturbed many-body ground states in the thermodynamic limit. Here, we study AOC in mesoscopic systems where the finite number of electrons, the confining geometry, interference effects and mesoscopic fluctuations give rise to novel behaviours not seen in bulk systems. In particular we consider two dimensional regular structures such as disc-like and rectangular quantum wells and realistic few electron quantum dots with parabolic confinement potential. Comparing the results with the chaotic case [M. Hentschel, D. Ullmo, and H. U. Baranger, Phys. Rev. Lett. 93, 176807 (2004)], we find characteristic differences such as shell effects. Our model of a rank-one perturbation describes, e.g., the core hole created in a x-ray absorption process where the AOC response of the system is experimentally accessible through the photoemission cross section.