Operational advantage of quantum resources in subchannel discrimination

Takagi, Ryuji; Regula, Bartosz; Bu, Kaifeng; Liu, Zi-Wen; Adesso, Gerardo

Abstract

One of the central problems in the study of quantum resource theories is to provide a given resource with an operational meaning, characterizing physical tasks in which the resource can give an explicit advantage over all resourceless states. We show that this can always be accomplished for all convex resource theories. We establish in particular that any resource state enables an advantage in a channel discrimination task, allowing for a strictly greater success probability than any state without the given resource. Furthermore, we find that the generalized robustness measure serves as an exact quantifier for the maximal advantage enabled by the given resource state in a class of subchannel discrimination problems, providing a universal operational interpretation to this fundamental resource quantifier. We also consider a wider range of subchannel discrimination tasks and show that the generalized robustness still serves as the operational advantage quantifier for several well-known theories such as entanglement, coherence, and magic.

Citation

Takagi, R., Regula, B., Bu, K., Liu, Z., & Adesso, G. (2019). Operational advantage of quantum resources in subchannel discrimination. Physical Review Letters, 122(14), Article 140402. https://doi.org/10.1103/physrevlett.122.140402

• Journal Article Type: Article
• Acceptance Date: Feb 2, 2019
• Online Publication Date: Apr 10, 2019
• Publication Date: Apr 12, 2019
• Deposit Date: Apr 29, 2019
• Publicly Available Date: Apr 29, 2019
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 122
• Issue: 14
• Article Number: 140402
• DOI: https://doi.org/10.1103/physrevlett.122.140402
• Keywords: General Physics and Astronomy
• Public URL: https://nottingham-repository.worktribe.com/output/1849264
• Publisher URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.140402
• Additional Information: Operational Advantage of Quantum Resources in Subchannel Discrimination, Ryuji Takagi, Bartosz Regula, Kaifeng Bu, Zi-Wen Liu, and Gerardo Adesso, Phys. Rev. Lett. 122, 140402.