| speaker: | Eric Jeckelmann University of Mainz, Germany |
| time: | Th. 10.04.03, 14:00 - 14:50 |
The Density-Matrix Renormalization Group (DMRG) was developed in the 1990's by S.R. White to extend Wilson's Numerical Renormalization Group to quantum lattice many-body problems such as the Hubbard model. A recent extension of the DMRG method allows one to calculate zero-temperature dynamical correlation functions in such models for all frequencies and with great accuracy. I will show that this method can also be used to calculate spectral functions in quantum impurity models. The approach is demonstrated on the single-impurity Anderson model. I will explain the present possibilities and limitations of the DMRG approach to quantum impurity problems and discuss future prospects, in particular, the extension to system with several impurities or bands and the treatment of bosonic degrees of freedom.