Distance measures to compare real and ideal quantum processes

Gilchrist, Alexei; Langford, Nathan K.; Nielsen, Michael A.

Distance measures to compare real and ideal quantum processes

Authors

Gilchrist, Alexei

Langford, Nathan K.

Nielsen, Michael A.

Description

With growing success in experimental implementations it is critical to identify a "gold standard" for quantum information processing, a single measure of distance that can be used to compare and contrast different experiments. We enumerate a set of criteria such a distance measure must satisfy to be both experimentally and theoretically meaningful. We then assess a wide range of possible measures against these criteria, before making a recommendation as to the best measures to use in characterizing quantum information processing.
15 pages; this version in line with published version