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Quantumness of noisy quantum walks: a comparison between measurement-induced disturbance and quantum discord

Quantum Physics 2011-07-01 v3

Abstract

Noisy quantum walks are studied from the perspective of comparing their quantumness as defined by two popular measures, measurement-induced disturbance (MID) and quantum discord (QD). While the former has an operational definition, unlike the latter, it also tends to overestimate non-classicality because of a lack of optimization over local measurements. Applied to quantum walks, we find that MID, while acting as a loose upper bound on QD, still tends to reflect correctly the trends in the behavior of the latter. However, there are regimes where its behavior is not indicative of non-classicality: in particular, we find an instance where MID increases with the application of noise, where we expect a reduction of quantumness.

Keywords

Cite

@article{arxiv.1012.5040,
  title  = {Quantumness of noisy quantum walks: a comparison between measurement-induced disturbance and quantum discord},
  author = {Balaji R. Rao and R. Srikanth and C. M. Chandrashekar and Subhashish Banerjee},
  journal= {arXiv preprint arXiv:1012.5040},
  year   = {2011}
}

Comments

5 pages with 4 figures, Published Version