English

Comparison of different measures for quantum discord under non-Markovian noise

Quantum Physics 2011-09-09 v3

Abstract

Two geometric measures for quantum discord were recently proposed by Modi et al. [Phys. Rev. Lett. 104, 080501 (2010)] and Dakic et al. [Phys. Rev. Lett. 105, 190502 (2010)]. We study the similarities and differences for total quantum correlations of Bell-diagonal states using these two geometry-based quantum discord and the original quantum discord. We show that, under non-Markovian dephasing channels, quantum discord and one of the geometric measures stay constant for a finite amount of time, but not the other geometric measure. However, all the three measures share a common sudden change point. Our study on critical point of sudden transition might be useful for keeping long time total quantum correlations under decoherence.

Keywords

Cite

@article{arxiv.1010.3521,
  title  = {Comparison of different measures for quantum discord under non-Markovian noise},
  author = {Zhenyu Xu and Wanli Yang and Xing Xiao and Mang Feng},
  journal= {arXiv preprint arXiv:1010.3521},
  year   = {2011}
}

Comments

10 pages, 3 figures submitted for publication