Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 45: Correlated Electrons: Poster Session

TT 45.49: Poster

Thursday, March 29, 2012, 15:00–19:00, Poster B

Properties of the Heisenberg two-leg Ladder using graph-based Continuous Unitary Transformations — •Johannes-Konstantin Splinter, Kris Cöster, and Kai Phillip Schmidt — Lehrstuhl für Theoretische Physik I, TU Dortmund, Germany

Continuous Unitary Transformations (CUTs) have established themselves to handle a variety of strongly correlated quantum many-body systems. The major challenge for the use of CUTs is to find a proper truncation scheme for the flow-equations. Here, we apply a recently developped new truncation scheme which is expected to give reliable effective low-energy models for gapped phases of quantum lattice models. The basic idea is to combine graph theory and CUTs. These intrinsically robust graph-based continuous unitary transformations (gCUTs) are used to calculate zero- and one-triplon properties of the antiferromagnetic S=1/2 Heisenberg ladder. In order to optimize the gCUTs, we implement the full symmetry group of the ladder system.