Direct Fidelity Estimation: Difference between revisions

This [https://arxiv.org/abs/1104.4695 example method] is used to certify than an experimental device prepares a desired quantum state. This is directly applicable to a pure quantum state and provides an estimate of the fidelity between the pure state and the actual arbitrary state in the lab, up to a constant additive error.  The method requires measuring only a constant number of Pauli expectation values, selected at random according to an importance-weighting rule.