Berlin 2005 – scientific programme

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MA: Magnetismus

MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65

MA 20.118: Poster

Monday, March 7, 2005, 14:00–18:00, Poster TU C

Entanglement and the phase diagram of spin-1 chains — •Clemens Müller-Gugenberger, Andreas Schadschneider, and Achim Rosch — Institut für Theoretische Physik, Universität zu Köln

Entanglement as a resource for quantum computing and communication is a central concept in quantum information science. Furthermore, it can be used to quantify nonclassical correlations in interacting systems.

Here, we investigate antiferromagnetic spin-1 chains. These systems are generically gapped and therefore robust against external disturbances. Already the case of isotropic interactions exhibits a rich phase diagram with several quantum phase transitions and the occurrence of topological order. While the model allows analytical treatment at special points of the phase diagram, for the general case a numerical treatment like the density matrix renormalisation group (DMRG) is necessary.

Using DMRG techniques, we investigate various entanglement properties in the ground state of the bilinear biquadratic spin-1 chain. We test the applicability of different entanglement measures to these models with special emphasis on the various phases, their phase transitions and the topological order.