Flow equation approach to heavy fermion systems
Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany
Corresponding author: a email@example.com
Revised: 27 September 2004
Published online: 26 November 2004
We use Wegner's flow equation method to investigate the infinite-U periodic Anderson model. We show that this method poses a new approach to the description of heavy fermion behaviour. Within this scheme we derive an effective Hamiltonian in which the c and f degrees of freedom are decoupled. By evaluating one-particle energies as well as correlation functions we find an electronic structure which comprises two gapped quasiparticle bands. We also address the lattice Kondo temperature, which shows a typical exponential dependence on the hybridisation energy. This energy scale exhibits a significant decrease compared to that of the single impurity Anderson model.
PACS: 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 71.27.+a – Strongly correlated electron systems; heavy fermions / 75.30.Mb – Valence fluctuation, Kondo lattice, and heavy-fermion phenomena
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004