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TT: Tiefe Temperaturen

TT 8: Mesoskopische Systeme

TT 8.11: Vortrag

Dienstag, 27. März 2001, 12:45–13:00, A

Kondo and mixed valence regimes in multi-level quantum dots — •Alexander Chudnovskiy¹ and Sergio Ulloa² — ¹Fachbereich Physik, Universität Halle, D-06108 Halle/Saale, Germany — ²Department of Physics and Astronomy, Ohio University, Athens, OH 45701 USA

We investigate the dependence of the ground state of a multi-level quantum dot on the coupling to an external fermionic system and on the interactions in the dot. As the coupling to the external system increases, the rearrangement of the effective energy levels in the dot signals the transition from the Kondo regime to a mixed valence (MV) regime. The MV regime in a two level dot is characterized by an intrinsic mixing of the levels in the dot, resulting in non-perturbative sub- and super-tunneling phenomena that strongly influence the Kondo effect.