1 Quantum erasure of decoherence
Francesco Buscemi, Giulio Chiribella, Giacomo Mauro D’Ariano
Abstract
Abstract. We consider the classical algebra of observables that are diagonal in a given or-thonormal basis, and define a complete decoherence process as a completely positive map that asymptotically converts any quantum observable into a diagonal one, while preserving the ele-ments of the classical algebra. For quantum systems in dimension two and three any decoherence process can be undone by collecting classical information from the environment and using such an information to restore the initial system state. As a relevant example, we illustrate the quantum eraser of Scully et al. [Nature 351, 111 (1991)] as an example of environment-assisted correction, and present the generalization of the eraser setup for d-dimensional systems. 1.