Year: 2014
Type: article
Abstract: If a quantum system A , which is initially correlated to another system, E , undergoes an evolution separated from E , then the correlation to E generally decreases. Here, we study the conditions under which the correlation disappears (almost) completely, resulting in a decoupling of A from E . We give a criterion for decoupling in terms of two smooth entropies, one quantifying the amount of initial correlation between A and E , and the other characterizing the mapping that describes the evolution of A . The criterion applies to arbitrary such mappings in the general one-shot setting. Furthermore, the criterion is tight for mappings that satisfy certain natural conditions. One-shot decoupling has a number of applications both in physics and information theory, e.g., as a building block for quantum information processing protocols. As an example, we give a one-shot state merging protocol and show that it is essentially optimal in terms of its entanglement consumption/production.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,990
Funders: National Science Foundation, University of Bristol, Agence Nationale de la Recherche, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Natural Sciences and Engineering Research Council of Canada, Engineering and Physical Sciences Research Council, FP7 Ideas: European Research Council, CHIST-ERA
Awards: Generalized (quantum) information theory, CQC - Composing Quantum Channels, G5599649393, G580951548, Information-theoretic methods for physics, G628552264, G7612340703, Theoretical Foundations of Quantum Cryptography, Information-theoretic methods for physics, Secure multi-party computation from physical assumptions, G993971353
OpenAlex ID: W2020582875