2013/10/31 by Christian Schwemmer, Lukas Knips, Daniel Richart +4 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.114.080403
published as Phys. Rev. Lett. 114, 080403 (2015) · 8 pages, 8 figures
arxiv created 2014/07/22 · arxiv updated 2015/03/18
Common tools for obtaining physical density matrices in experimental quantum state tomography are shown here to cause systematic errors. For example, using maximum likelihood or least squares optimization for state reconstruction, we observe a systematic underestimation of the fidelity and an overestimation of entanglement. A solution for this problem can be achieved by a linear evaluation of the data yielding reliable and computational simple bounds including error bars.