English

Entangling Power of Permutations

Quantum Physics 2007-05-23 v2

Abstract

The notion of entangling power of unitary matrices was introduced by Zanardi, Zalka and Faoro [PRA, 62, 030301]. We study the entangling power of permutations, given in terms of a combinatorial formula. We show that the permutation matrices with zero entangling power are, up to local unitaries, the identity and the swap. We construct the permutations with the minimum nonzero entangling power for every dimension. With the use of orthogonal latin squares, we construct the permutations with the maximum entangling power for every dimension. Moreover, we show that the value obtained is maximum over all unitaries of the same dimension, with possible exception for 36. Our result enables us to construct generic examples of 4-qudits maximally entangled states for all dimensions except for 2 and 6. We numerically classify, according to their entangling power, the permutation matrices of dimension 4 and 9, and we give some estimates for higher dimensions.

Cite

@article{arxiv.quant-ph/0502040,
  title  = {Entangling Power of Permutations},
  author = {Lieven Clarisse and Sibasish Ghosh and Simone Severini and Anthony Sudbery},
  journal= {arXiv preprint arXiv:quant-ph/0502040},
  year   = {2007}
}

Comments

8 pages. We have deleted the appendix. We have pointed out that our result enables to construct generic examples of 4-qudits maximally entangled states for all dimensions except for 2 and 6. Accepted for publication in Phys. Rev. A