Determination of ground-state properties in quantum spin systems by single-qubit unitary operations and entanglement excitation energies

@article{citeulike:2502766, abstract = {We introduce a method for analyzing ground-state properties of quantum many-body systems, based on the characterization of separability and entanglement by single subsystem unitary operations. We apply the method to the study of the ground-state structure of several interacting spin-1/2 models, described by Hamiltonians with different degrees of symmetry. We show that the approach based on single-qubit unitary operations allows us to introduce \“entanglement excitation energies,\” a set of observables that can characterize ground-state properties, including the quantification of single-site entanglement and the determination of quantum critical points. The formalism allows us to identify the existence and location of factorization points, and a purely quantum \“transition of entanglement\” that occurs at the approach of factorization. This kind of quantum transition is characterized by a diverging ratio of excitation energies associated with single-qubit unitary operations.}, author = {Giampaolo, S. M. and Illuminati, F. and Verrucchi, P. and De Siena, S. }, citeulike-article-id = {2502766}, doi = {http://dx.doi.org/10.1103/PhysRevA.77.012319}, journal = {Physical Review A (Atomic, Molecular, and Optical Physics)}, keywords = {2008, entanglement, quantum\_magnetism, quantum\_world, verrucchi}, number = {1}, posted-at = {2008-03-10 17:42:40}, priority = {2}, publisher = {APS}, title = {Determination of ground-state properties in quantum spin systems by single-qubit unitary operations and entanglement excitation energies}, url = {http://dx.doi.org/10.1103/PhysRevA.77.012319}, volume = {77}, year = {2008} }

TY - JOUR ID - citeulike:2502766 L3 - citeulike-article-id:2502766 N2 - We introduce a method for analyzing ground-state properties of quantum many-body systems, based on the characterization of separability and entanglement by single subsystem unitary operations. We apply the method to the study of the ground-state structure of several interacting spin-1/2 models, described by Hamiltonians with different degrees of symmetry. We show that the approach based on single-qubit unitary operations allows us to introduce “entanglement excitation energies,” a set of observables that can characterize ground-state properties, including the quantification of single-site entanglement and the determination of quantum critical points. The formalism allows us to identify the existence and location of factorization points, and a purely quantum “transition of entanglement” that occurs at the approach of factorization. This kind of quantum transition is characterized by a diverging ratio of excitation energies associated with single-qubit unitary operations. IS - 1 JF - Physical Review A (Atomic, Molecular, and Optical Physics) TI - Determination of ground-state properties in quantum spin systems by single-qubit unitary operations and entanglement excitation energies PB - APS VL - 77 KW - 2008 KW - entanglement KW - quantum_magnetism KW - quantum_world KW - verrucchi AU - Giampaolo, SM AU - Illuminati, F AU - Verrucchi, P AU - De Siena, S PY - 2008/// UR - http://dx.doi.org/10.1103/PhysRevA.77.012319 ER -