Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 38: Correlated Electrons: Low-dimensional Systems - Models 1
TT 38.1: Vortrag
Donnerstag, 26. März 2009, 09:30–09:45, HSZ 301
Thermally Activated Peierls Dimerization in Ferromagnetic Spin Chains — •Jesko Sirker1, Alexander Herzog1, Andrzej M. Oles1,2, and Peter Horsch1 — 1Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany — 2Marian Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, PL-30059 Kraków, Poland
We demonstrate that a Peierls dimerization can occur in ferromagnetic spin chains activated by thermal fluctuations [1]. The dimer order parameter and entanglement measures are studied as functions of the modulation of the magnetic exchange interaction and temperature, using a spin-wave theory and the density-matrix renormalization group. We discuss the case where a periodic modulation is caused by spin-phonon coupling and the case where electronic states effectively induce such a modulation. The importance of the latter for a number of transition metal oxides is highlighted.
[1] Phys. Rev. Lett. 101, 157204 (2008)