In the paper "Efficient Measurement of Quantum Dynamics via Compressive Sensing" Shabani Et. al (2011) [arXiv:0910.5498], The full process tomography of two-photon is performed as: Preparing 16 pairwise combinations of the 4 input states $\{|H\rangle,|V\rangle,|D\rangle,|R\rangle\}$ and, for each input, measuring 36 two-qubit combinations of the observables $\{|H\rangle,|V\rangle,|D\rangle,|A\rangle,|R\rangle,|L\rangle\}, \quad$ where $|D(A)\rangle=(|H\rangle$ $\pm |V\rangle) / \sqrt{2}$ and $\mid R(L)\rangle=(|H\rangle \pm i| V\rangle) / \sqrt{2}$. These $16\times 36=576$ input-output configurations represent an overcomplete set which allows the best possible estimate of the quantum process, denoted $\chi_{576}$.

Why are 36 pairs of observables for each input state used here?



Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.