Europhys. Lett.
Volume 73, Number 6, March 2006
Page(s) 913 - 919
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 10 February 2006
Europhys. Lett., 73 (6), pp. 913-919 (2006)
DOI: 10.1209/epl/i2005-10479-1

Electron transfer in donor-acceptor systems: Many-particle effects and influence of electronic correlations

S. Tornow1, N.-H. Tong2 and R. Bulla1

1  Theoretische Physik III, Elektronische Korrelationen und Magnetismus Universität Augsburg - 86135 Augsburg, Germany
2  Institut für Theorie der Kondensierten Materie, Universität Karlsruhe 76128 Karlsruhe, Germany

received 6 October 2005; accepted in final form 24 January 2006
published online 10 February 2006

We investigate electron transfer processes in donor-acceptor systems with a coupling of the electronic degrees of freedom to a common bosonic bath. The model allows to study many-particle effects and the influence of the local Coulomb interaction U between electrons on donor and acceptor sites. Using the non-perturbative numerical renormalization group approach we find distinct differences between the electron transfer characteristics in the single- and two-particle subspaces. We calculate the critical electron-boson coupling $\alpha_\ab{c}$ as a function of U and show results for density-density correlation functions in the whole parameter space. The possibility of many-particle (bipolaronic) and Coulomb-assisted transfer is discussed.

71.27.+a - Strongly correlated electron systems; heavy fermions.
34.70.+e - Charge transfer.
82.39.Jn - Charge (electron, proton) transfer in biological systems.

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