English

Optimality of programmable quantum measurements

Quantum Physics 2009-11-13 v1

Abstract

We prove that for a programmable measurement device that approximates every POVM with an error δ\le \delta, the dimension of the program space has to grow at least polynomially with 1δ\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)].

Keywords

Cite

@article{arxiv.quant-ph/0602084,
  title  = {Optimality of programmable quantum measurements},
  author = {David Perez-Garcia},
  journal= {arXiv preprint arXiv:quant-ph/0602084},
  year   = {2009}
}