Andrea Fubini, Stephan Haas, Tommaso Roscilde, Valerio Tognetti, Paola Verrucchi
Published 2006-05-24Version 1
Entanglement represents a pure quantum effect involving two or more particles. Spin systems are good candidates for studying this effect and its relation with other collective phenomena ruled by quantum mechanics. While the presence of entangled states can be easily verified, the quantitative estimate of this property is still under investigation. One of the most useful tool in this framework is the concurrence whose definition, albeit limited to $S=1/2$ systems, can be related to the correlators. We consider quantum spin systems defined along chains and square lattices, and described by Heisenberg-like Hamiltonians: our goal is to clarify the relation between entanglement and quantum phase transitions, as well as that between the concurrence the and the specific quantum state of the system.
Comments: 10 pages, 2 figures. To appear in "Open Systems & Information Dynamics" (2006)
Signatures of quantum phase transitions after quenches in quantum chaotic one-dimensional systems
The quantum phase transition and correlations in the multi-spin-boson model
Breakdown of a Magnetization Plateau in Ferrimagnetic Mixed Spin-(1/2,S) Heisenberg Chains Due to a Quantum Phase Transition Towards the Luttinger Spin Liquid
