Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 26: Spin Dynamics / Spin Torque IV
MA 26.10: Vortrag
Donnerstag, 25. März 2010, 16:45–17:00, H10
Spin dynamics in a ferromagnetic spin-orbital chain beyond mean-field decoupling — •Alexander Herzog1, Andrzej Oleś1,2, Peter Horsch1, and Jesko Sirker1,3 — 1Max Planck Institute for Solid State Research, Stuttgart, Germany — 2Marian Smoluchowski Institute of Physics, Jagellonian University, Kraków, Poland — 3Technische Universität Kaiserslautern, Fachbereich Physik, Kaiserslautern, Germany
We study the spin dynamics and thermodynamics of a one-dimensional spin-orbital model relevant for transition metal oxides. In mean-field decoupling this model shows a dimerized phase at intermediate temperatures while the spins order ferromagnetically in the ground state. Using a modified spin-wave theory we calculate the dynamical spin structure factor in the uniform and dimerized phase. We then address the question how the spin dynamics is affected if the spin-orbital coupling is taken into account beyond mean-field. Finally we also study corrections to thermodynamic quantities beyond the mean-field decoupling and compare with a numerical solution of the model obtained by the density-matrix renormalization group.