Editing Direct Fidelity Estimation (section)

==Properties==
* '''The figure of merit''': Fidelity
* This protocol requires multiple copies of the final state. The expected numbers of copies are: <math>E(m) \leq 1 + \frac{1}{\epsilon^2\delta} + \frac{2d}{\epsilon^2}log(2/\delta)</math>
* This protocol is applicable to a large class of quantum states and requires minimal experimental resources 
* This protocol is faster than full tomography by a factor of $d$, the dimension of the state space
* Measurement of an only constant number of Pauli observables is required however each measurement needs to be repeated. The number of repetitions is <math>O(d)</math> in the worst case, however, in many cases of practical interest, it is smaller.
* This protocol used a fixed number of Pauli observables, depending on the additive error and failure probability, and is independent of the size of the system
* This method allows one to directly measure the entanglement fidelity and average fidelity of the entire circuit, rather than inferring it from tomography performed on individual gates.