Measures and applications of quantum correlations

Adesso, Gerardo; Bromley, Thomas R.; Cianciaruso, Marco

Abstract

Quantum information theory is built upon the realisation that quantum resources like coherence and entanglement can be exploited for novel or enhanced ways of transmitting and manipulating information, such as quantum cryptography, teleportation, and quantum computing. We now know that there is potentially much more than entanglement behind the power of quantum information processing. There exist more general forms of non-classical correlations, stemming from fundamental principles such as the necessary disturbance induced by a local measurement, or the persistence of quantum coherence in all possible local bases. These signatures can be identified and are resilient in almost all quantum states, and have been linked to the enhanced performance of certain quantum protocols over classical ones in noisy conditions. Their presence represents, among other things, one of the most essential manifestations of quantumness in cooperative systems, from the subatomic to the macroscopic domain. In this work we give an overview of the current quest for a proper understanding and characterisation of the frontier between classical and quantum correlations (QCs) in composite states. We focus on various approaches to define and quantify general QCs, based on different yet interlinked physical perspectives, and comment on the operational significance of the ensuing measures for quantum technology tasks such as information encoding, distribution, discrimination and metrology. We then provide a broader outlook of a few applications in which quantumness beyond entanglement looks fit to play a key role.

Citation

Adesso, G., Bromley, T. R., & Cianciaruso, M. (2016). Measures and applications of quantum correlations. Journal of Physics A: Mathematical and Theoretical, 49(47), https://doi.org/10.1088/1751-8113/49/47/473001

• Journal Article Type: Article
• Acceptance Date: Oct 7, 2016
• Publication Date: Nov 3, 2016
• Deposit Date: Feb 24, 2017
• Publicly Available Date: Feb 24, 2017
• Journal: Journal of Physics A: Mathematical and Theoretical
• Print ISSN: 1751-8113
• Electronic ISSN: 1751-8121
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 49
• Issue: 47
• DOI: https://doi.org/10.1088/1751-8113/49/47/473001
• Keywords: Quantum correlations, quantum discord, quantum technologies
• Public URL: https://nottingham-repository.worktribe.com/output/830102
• Publisher URL: http://dx.doi.org/10.1088/1751-8113/49/47/473001
• Related Public URLs: https://arxiv.org/abs/1605.00806
• Additional Information: This is an author-created, un-copyedited version of an article accepted for publication/published in Journal of Physics A: Mathematical and Theoretical. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/1751-8113/49/47/473001 .
• Contract Date: Feb 24, 2017