Regensburg 2004 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
TT: Tiefe Temperaturen
TT 24: Postersitzung III: Korrelierte Elektronen, ”Orbital Physics”
TT 24.10: Poster
Wednesday, March 10, 2004, 14:30–19:00, Poster A
Functional RG for Luttinger liquids with impurities — •Sabine Andergassen1, Tilman Enss1, Volker Meden2, Walter Metzner1, Ulrich Schollwöck3, and Kurt Schönhammer2 — 1Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart — 2Institut für Theoretische Physik, Universität Göttingen, D-37073 Göttingen — 3Sektion Physik, Universität München, D-80333 München
Using a functional RG we compute the flow of the renormalized impurity potential for a single impurity in a Luttinger liquid over the entire energy range from the microscopic scale of a lattice-fermion model down to the low-energy limit. The non-perturbative method provides a complete real-space picture of the effective impurity potential. Further developments of the functional RG approach including 2-particle vertex renormalization considerably improve the quantitative accuracy of the results in particular at moderate interaction strenghts, which are compared to exact DMRG results. Focusing on the spectral properties of the single-particle excitations near an impurity or boundary and on the density profile, we confirm the universality of the open chain fixed point, but it turns out that very large systems are required to reach the asymptotic regime for realistic choices of the impurity and interaction parameters.