Strongly Correlated Systems

Many strongly correlated systems are at the forefront of
experimental and theoretical research in condensed matter physics,
among them High Temperature Superconductors, Heavy Fermions,
Manganites, and Vanadates.
These materials are modeled by simplified theoretical
descriptions like the Heisenberg model, Hubbard model, Anderson Impurity model,
Kondo models, and by combinations of these models, especially for the very complicated and
intriguing Manganites which have many relevant degrees of
freedom, including dynamical Jahn-Teller lattice modes.

Theoretical investigations in these areas are extremely challenging,
since the importance of strong correlations causes most traditional methods to work only
with very limited applicability or fail altogether.
Analytical approaches are hampered by approximations which are often difficult to control.
Numerical techniques are often limited in the range of accessible system size and temperature.

Our group studies strongly correlated systems and concentrates on applying numerical approaches like

together with supporting analytical approaches.
We put special emphasis on developing and improving new techniques without systematical errors,
to extend the accessible range of models and physics,
and to simultaneously study the interplay of different dynamical degrees of freedom.

We have, e.g.,  been investigating