An information-theoretic measure for the computational fidelity of physical processes

Abstract

An information-theoretic measure is proposed for the fidelity of classical information processing operations implemented in quantum mechanical hardware. This fidelity measure quantifies the degree to which a specified logic operation - a mapping from logical inputs to logical outputs - is mirrored in the mapping of initial states into distinguishable final states of a quantum system by a physical process. We formally define the computational fidelity, discuss its characteristics, illustrate its application, and comment on its connection to fundamental limits on the physical cost of information processing.