Regensburg 2007 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

DY: Fachverband Dynamik und Statistische Physik

DY 30: Poster II

DY 30.11: Poster

Donnerstag, 29. März 2007, 16:00–18:00, Poster D

Nonlinear integral equations for the thermodynamics of the Uimin-Sutherland model — •Jens Damerau and Andreas Kluemper — Fachbereich C – Physik, Bergische Universität Wuppertal, 42097 Wuppertal, Germany

We investigate the thermodynamical properties of integrable one-dimensional spin-chains of Uimin-Sutherland type. This class includes several interesting models like the spin-1/2 Heisenberg model, the t−J model, the SU(4)-symmetric spin-orbital model and certain spin-ladder systems. We derive well-posed finite sets of nonlinear integral equations (NLIE) which allow for the numerical evaluation at arbitrary finite temperature. Analytical solutions are possible in the high- and low-temperature limits. In the low-temperature regime, we find divergences of the magnetic susceptibilities at critical fields and logarithmic singularities for zero magnetic field. In comparison to other recently derived NLIE, the evaluation at low temperature poses no problem in our formulation.