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arXiv quant-ph/95070081995-07-14quant-ph

Minimum Decision Cost for Quantum Ensembles

Dorje Brody, Bernhard Meister

备注：: 11 pages, uses RevTex
发表信息：: Phys.Rev.Lett. 76 (1996) 1-5
DOI：: 10.1103/PhysRevLett.76.1

英文摘要：

For a given ensemble of $N$ independent and identically prepared particles, we calculate the binary decision costs of different strategies for measurement of polarised spin 1/2 particles. The result proves that, for any given values of the prior probabilities and any number of constituent particles, the cost for a combined measurement is always less than or equal to that for any combination of separate measurements upon sub-ensembles. The Bayes cost, which is that associated with the optimal strategy (i.e., a combined measurement) is obtained in a simple closed form.

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