Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications

This PhD Dissertation collects results of my own work on the topic of continuous variable (CV) quantum teleportation, which is one of the most important applications of quantum entanglement, as well as on the understanding, quantification, detection, and applications of a type of quantum correlatio...

Full description

Bibliographic Details
Main Author: Kogias, Ioannis
Format: Thesis (University of Nottingham only)
Language:English
Published: 2016
Subjects:
Online Access:https://eprints.nottingham.ac.uk/34584/
_version_ 1848794888768847872
author Kogias, Ioannis
author_facet Kogias, Ioannis
author_sort Kogias, Ioannis
building Nottingham Research Data Repository
collection Online Access
description This PhD Dissertation collects results of my own work on the topic of continuous variable (CV) quantum teleportation, which is one of the most important applications of quantum entanglement, as well as on the understanding, quantification, detection, and applications of a type of quantum correlations known as Einstein-Podolsky-Rosen (EPR) steering, for both bipartite and multipartite systems and with a main focus on CV systems. For the first results, we examine and compare two fundamentally different teleportation schemes; the well-known continuous variable scheme of Vaidman, Braunstein and Kimble, and a recently proposed hybrid scheme by Andersen and Ralph. We analyse the teleportation of ensembles of arbitrary pure single-mode Gaussian states using these schemes and compare their performance against classical strategies that utilize no entanglement (benchmarks). Our analysis brings into question any advantage due to non-Gaussianity for quantum teleportation of Gaussian states. For the second part of the results, we study bipartite EPR-steering. We propose a novel powerful method to detect steering in quantum systems of any dimension in a systematic and hierarchical way. Our method includes previous results of the literature as special cases on one hand, and goes beyond them on the other. We proceed to the quantification of steering-type correlations, and introduce a measure of steering for arbitrary bipartite Gaussian states, prove many useful properties, and provide with an operational interpretation of the proposed measure in terms of the key rate in one-sided device independent quantum key distribution. Finally, we show how the Gaussian steering measure gives a lower bound to a more general quantifier of which Gaussian states are proven to be extremal. We proceed to the study of multipartite steering, and derive laws for the distribution of Gaussian steering among different parties in multipartite Gaussian states. We define an indicator of collective steering-type correlations, which is interpreted operationally in terms of the guaranteed secret key rate in the multi-party cryptographic task of quantum secret sharing. The final results look at the cryptographical task of quantum secret sharing, whose security has remained unproven almost two decades after its original conception. By utilizing intuition and ideas from steering, we manage to establish for the first time an unconditional security proof for CV entanglement-based quantum secret sharing schemes, and demonstrate their practical feasibility. Our results establish quantum secret sharing as a viable and practically relevant primitive for quantum communication technologies.
first_indexed 2025-11-14T19:23:21Z
format Thesis (University of Nottingham only)
id nottingham-34584
institution University of Nottingham Malaysia Campus
institution_category Local University
language English
last_indexed 2025-11-14T19:23:21Z
publishDate 2016
recordtype eprints
repository_type Digital Repository
spelling nottingham-345842025-02-28T11:49:59Z https://eprints.nottingham.ac.uk/34584/ Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications Kogias, Ioannis This PhD Dissertation collects results of my own work on the topic of continuous variable (CV) quantum teleportation, which is one of the most important applications of quantum entanglement, as well as on the understanding, quantification, detection, and applications of a type of quantum correlations known as Einstein-Podolsky-Rosen (EPR) steering, for both bipartite and multipartite systems and with a main focus on CV systems. For the first results, we examine and compare two fundamentally different teleportation schemes; the well-known continuous variable scheme of Vaidman, Braunstein and Kimble, and a recently proposed hybrid scheme by Andersen and Ralph. We analyse the teleportation of ensembles of arbitrary pure single-mode Gaussian states using these schemes and compare their performance against classical strategies that utilize no entanglement (benchmarks). Our analysis brings into question any advantage due to non-Gaussianity for quantum teleportation of Gaussian states. For the second part of the results, we study bipartite EPR-steering. We propose a novel powerful method to detect steering in quantum systems of any dimension in a systematic and hierarchical way. Our method includes previous results of the literature as special cases on one hand, and goes beyond them on the other. We proceed to the quantification of steering-type correlations, and introduce a measure of steering for arbitrary bipartite Gaussian states, prove many useful properties, and provide with an operational interpretation of the proposed measure in terms of the key rate in one-sided device independent quantum key distribution. Finally, we show how the Gaussian steering measure gives a lower bound to a more general quantifier of which Gaussian states are proven to be extremal. We proceed to the study of multipartite steering, and derive laws for the distribution of Gaussian steering among different parties in multipartite Gaussian states. We define an indicator of collective steering-type correlations, which is interpreted operationally in terms of the guaranteed secret key rate in the multi-party cryptographic task of quantum secret sharing. The final results look at the cryptographical task of quantum secret sharing, whose security has remained unproven almost two decades after its original conception. By utilizing intuition and ideas from steering, we manage to establish for the first time an unconditional security proof for CV entanglement-based quantum secret sharing schemes, and demonstrate their practical feasibility. Our results establish quantum secret sharing as a viable and practically relevant primitive for quantum communication technologies. 2016-12-14 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/34584/1/I.Kogias_PhD_CorrectedVersion.pdf Kogias, Ioannis (2016) Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications. PhD thesis, University of Nottingham. quantum mechanics entanglement quantum information quantum cryptography quantum teleportation steering einstein-podolsky-rosen paradox EPR paradox einstein-podolsky-rosen steering EPR steering continuous variables steering detection Gaussian steering measures steering quantifiers multipartite steering monogamy secret sharing device independent
spellingShingle quantum mechanics
entanglement
quantum information
quantum cryptography
quantum teleportation
steering
einstein-podolsky-rosen paradox
EPR paradox
einstein-podolsky-rosen steering
EPR steering
continuous variables
steering detection
Gaussian
steering measures
steering quantifiers
multipartite steering
monogamy
secret sharing
device independent
Kogias, Ioannis
Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications
title Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications
title_full Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications
title_fullStr Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications
title_full_unstemmed Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications
title_short Entanglement, Einstein-Podolsky-Rosen steering and cryptographical applications
title_sort entanglement, einstein-podolsky-rosen steering and cryptographical applications
topic quantum mechanics
entanglement
quantum information
quantum cryptography
quantum teleportation
steering
einstein-podolsky-rosen paradox
EPR paradox
einstein-podolsky-rosen steering
EPR steering
continuous variables
steering detection
Gaussian
steering measures
steering quantifiers
multipartite steering
monogamy
secret sharing
device independent
url https://eprints.nottingham.ac.uk/34584/