Experimentally feasible measures of distance between quantum operations

TytułExperimentally feasible measures of distance between quantum operations
Publication TypeJournal Article
Rok publikacji2011
AutorzyPuchała Z, Miszczak J.A., Gawron P, Gardas B.
JournalQuantum Information Processing
Volume10
Pagination1–12
ISSN1570-0755
AbstractWe present two measures of distance between quantum processes which can be measured directly in laboratory without resorting to process tomography. The measures are based on the superfidelity, introduced recently to provide an upper bound for quantum fidelity. We show that the introduced measures partially fulfill the requirements for distance measure between quantum processes. We also argue that they can be especially useful as diagnostic measures to get preliminary knowledge about imperfections in an experimental setup. In particular we provide quantum circuit which can be used to measure the superfidelity between quantum processes. We also provide a physical interpretation of the introduced metrics based on the continuity of channel capacity.