Full Quantum Process Tomography with Linear inversion: Difference between revisions

* Quantum operations can also be used to describe measurements. For each measurement outcome, <math>i</math>, there is a associated quantum operation <math>\varepsilon_i</math>. The corresponding state change is given by <math>\rho \xrightarrow{} \varepsilon_i(\rho)/tr(\varepsilon_i(\rho))</math> where the probability of the measurement outcome occurring is <math>p_i = tr(\varepsilon_i(\rho))</math>. To determine the process the steps are the same, except the measurement has to be taken a large enough number of times that the probability pi can be reliably estimated. Next <math>\rho^{'}_{j}</math> is determined using tomography, thus obtaining <math>\varepsilon_i(\rho_j) = tr(\varepsilon_i(\rho_j))\rho^{'}_{j}</math> for each input <math>\rho_j</math>. The other steps remain to same to estimate <math>\varepsilon_i</math>.

'''Input''': <math>p_j, j = 1, ..., N^2</math>