%0 Journal Article
%T Optimality of programmable quantum measurements
%A David Perez-Garcia
%J Physics
%D 2006
%I arXiv
%R 10.1103/PhysRevA.73.052315
%X We prove that for a programmable measurement device that approximates every POVM with an error $\le \delta$, the dimension of the program space has to grow at least polynomially with $\frac{1}{\delta}$. 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)].
%U http://arxiv.org/abs/quant-ph/0602084v1