Estimating Quantum Correlations in Dimerized Spin Systems Through a Correlated Mean Field Approach

J.M. MATERA; C. A. LAMAS; R. D. ROSSIGNOLI; CANOSA, N.; A. P. BOETTE

Mar del Plata

Congreso; Quantum Optics VII; 2014

Latin American Committee for Quantum Optics

Abstract: Matera, J. M., Rossignoli, R. D., Lamas, C. A., Canosa, N. B., Boette, A. In many-body physics, the Mean Field Theory (MFT) provides an intuitive starting point for the evaluation of local observables and some correlations. When systems develop just weak quantum correlations, a linear response theory built over this approximation allows us to recover many of the main features of their quantum correlations. However, due the fact that the approximation is based on fully factorized states, this method is not able to deal with systems which develop a large amount of entanglement among its components. In this contribution we shall employ a Correlated Mean Field scheme to study quantum correlations for the case of systems which presents strong but localized quantum correlations. Applications to the estimation of pairwise, bipartite and multipartite entanglement in the zig-zag ladders and other dimerized chains are discussed. Besides, analytical results from both a linear response theory and a perturbative approach over this correlated mean field state are presented, as well as their comparison with numerical results. J. M. Matera, C. A. Lamas, arXiv:1403.3737 (2014) J. M. Matera, R. Rossignoli, and N. Canosa, Phys. Rev. A 86, 062324 (2012) Raul Rossignoli, Norma Canosa, Juan Mauricio Matera, Phys. Rev. A 83, 042328 (2011) J. M. Matera, R. Rossignoli, N. Canosa, Physical Review A 82, 052332 (2010).