IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Evaluation of entanglement measures in spin systems with the random phase approximation
Autor/es:
CANOSA, NORMA; MATERA, JUAN MAURICIO; ROSSIGNOLI, RAUL
Revista:
JOURNAL OF RUSSIAN LASER RESEARCH
Editorial:
SPRINGER
Referencias:
Año: 2011 vol. 32 p. 322 - 330
ISSN:
1071-2836
Resumen:
We discuss a general formalism based on the mean field plus random phase approximation (RPA) for the evaluation of entanglement measures in the ground state of spin systems. The method provides a tractable scheme for determining the entanglement entropy as well as the negativity of finite subsystems, which becomes analytic in the case of systems with translational invariance, in one or D dimensions. The approach improves as the spin increases, and also as the interaction range or connectivity increases. Illustrative results for different types of entanglement entropies (single site, block and comb) in the ground state of a small spin lattice with ferromagnetic type XY couplings in a transverse field are shown and compared with the exact numerical result. Effects arising from symmetry breaking at the mean field level are also discussed.