Half the entanglement in critical systems is distillable from a single specimen
Orus, R. ; Latorre, J. I. ; Eisert, J. ; Cramer, M.
arXiv, 0509023 / Harvested from arXiv
Text on arXiv
We establish that the leading critical scaling of the single-copy entanglement is exactly one half of the entropy of entanglement of a block in critical infinite spin chains in a general setting, using methods of conformal field theory. Conformal symmetry imposes that the single-copy entanglement for critical many-body systems scales as E_1(\rho_L)=(c/6) \log L- (c/6) (\pi^2/\log L) + O(1/L), where L is the number of constituents in a block of an infinite chain and c corresponds to the central charge. This proves that from a single specimen of a critical chain, already half the entanglement can be distilled compared to the rate that is asymptotically available. The result is substantiated by a quantitative analysis for all translationally invariant quantum spin chains corresponding to general isotropic quasi-free fermionic models. An analytic example of the XY model shows that away from criticality the above simple relation is only maintained near the quantum phase transition point.
Publié le : 2005-09-02
Classification:  Quantum Physics,  Condensed Matter - Statistical Mechanics,  Mathematical Physics 
@article{0509023,
     author = {Orus, R. and Latorre, J. I. and Eisert, J. and Cramer, M.},
     title = {Half the entanglement in critical systems is distillable from a single
  specimen},
     journal = {arXiv},
     volume = {2005},
     number = {0},
     year = {2005},
     language = {en},
     url = {http://dml.mathdoc.fr/item/0509023}
}

Orus, R.; Latorre, J. I.; Eisert, J.; Cramer, M. Half the entanglement in critical systems is distillable from a single
  specimen. arXiv, Tome 2005 (2005) no. 0, . http://gdmltest.u-ga.fr/item/0509023/