48 research outputs found
The SWITCH test for discriminating quantum evolutions
We propose a quantum circuit to discriminate between two arbitrary quantum
evolution operators. It permits to test the equality of two quantum operators
and to estimate a fidelity measure of them. The relation of the proposal to the
SWAP test for discriminating two quantum states is analyzed. We also discuss
potential applications for the discrimination of quantum channels and possible
laboratory implementations with light along the same lines of recent
experimental realizations of quantum superpositions of causal orders exploiting
the different degrees of freedom of photons.Comment: 5 pages, 8 figures. Comments welcom