Publikationsserver der RWTH Aachen University
Grundzustandseigenschaften von anisotropen antiferromagnetischen Heisenberg-Ketten mit Spin S = 1
Abstract
dc:descriptionIn this thesis ground state properties of S = 1 spin chains with exchange and single-ion anisotropy are analysed. Following earlier publications two cases are mainly considered: A fixed ratio of the two anisotropies as well as a fixed and strong exchange anisotropy. The method primarily employed is the density matrix renormalization group (DMRG) for a finite chain length and in the thermodynamic limit (iDMRG). The phase diagrams of the quantum spin chain and the corresponding classical model are compared for the first time. Thereby the similarity of the phase diagrams, the correspondence of the phases and the striking differences are elucidated. The various phases of the quantum model include antiferromagnetic, ferromagnetic, spin liquid and supersolid phases. Their properties are discussed in detail. Analysing the correlation functions and using a correspondence to Luttinger liquids one can distinguish commensurate and incommensurate regions of the spin liquid phase. For different parameters the spin liquid phase may be subdivided into regions of ferroquadrupolar and spin-density-wave ordering. Some of the quantum phase transitions between the various phases are studied. Particularly the transition between the spin liquid and the supersolid phase is identified to be in the two-dimensional Ising universality class.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2012
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Peters, David
- Contributors dc:contributor
-
- Selke, Walter
Subjects
dc:subject × 15Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger
Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:publications.rwth-aachen.de:62951