Holger Frahm – Institute of Theoretical Physics

Holger Frahm's Research Group

The focus of our work is the construction of integrable models in one space dimension and their analysis to study correlation effects in quantum many-body systems (and in related classical two-dimensional lattice models) in the context of (mathematically) exact solutions. This allows for the computation of observables in systems of arbitrary size thereby providing valuable insights into their dependence on coupling constants or external fields as well as the signatures of impurities in otherwise perfect systems.

Fields of Interest

Quantum spin chains and non-Abelian anyons:
integrable boundary conditions, finite size spectrum, critical properties, persistent currents
Supersymmetric vertex models:
quantum symmetries, critical properties, low energy effective theories
Quantum impurities:
Kondo and Anderson models, thermodynamic properties, quantum phase transitions
Strongly correlated electron systems:
Hubbard-, t–J-models and generalizations