Quantum phase transitions in the bosonic single-impurity Anderson model
Theoretische Physik III, Elektronische Korrelationen und Magnetismus, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
Corresponding author: a email@example.com
Revised: 29 March 2007
Published online: 4 May 2007
We consider a quantum impurity model in which a bosonic impurity level is coupled to a non-interacting bosonic bath, with the bosons at the impurity site subject to a local Coulomb repulsion U. Numerical renormalization group calculations for this bosonic single-impurity Anderson model reveal a zero-temperature phase diagram where Mott phases with reduced charge fluctuations are separated from a Bose-Einstein condensed phase by lines of quantum critical points. We discuss possible realizations of this model, such as atomic quantum dots in optical lattices. Furthermore, the bosonic single-impurity Anderson model appears as an effective impurity model in a dynamical mean-field theory of the Bose-Hubbard model.
PACS: 05.10.Cc – Renormalization group methods / 05.30.Jp – Boson systems / 03.75.Nt – Other Bose-Einstein condensation phenomena
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007