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Optimality of programmable quantum measurements

David Perez-Garcia
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Abstract

We prove that for a programmable measurement device that approximates every POVM with an error $\le δ$, the dimension of the program space has to grow at least polynomially with $\frac{1}δ$. In the case of qubits we can improve the general result by showing a linear growth. This proves the optimality of the programmable measurement devices recently designed in [G. M. D'Ariano and P. Perinotti, Phys. Rev. Lett. \textbf{94}, 090401 (2005)].

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David Perez-Garcia. 2006-02-09. Optimality of programmable quantum measurements. https://doi.org/10.1103/physreva.73.052315

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