Quantum correlations in information theory

Girolami, Davide (2013) Quantum correlations in information theory. PhD thesis, University of Nottingham.

[thumbnail of phd thesis]
Preview
PDF (phd thesis) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (2MB) | Preview

Abstract

The project concerned the study of quantum correlations (QC) in compound systems, i.e. statistical correlations more general than entanglement which are predicted by quantum mechanics but not described in any classical scenario. I aimed to understand the technical and operational properties of the measures of QC, their interplay with entanglement quantifiers and the experimental accessibility.

In the first part of my research path, after having acquired the conceptual and technical rudiments of the project, I provided solutions for some computational issues: I developed analytical and numerical algorithms for calculating bipartite QC in finite dimensional systems. Then, I tackled the problem of the experimental detection of QC. There is no Hermitian operator associated with entanglement measures, nor with QC ones. However, the information encoded in a density matrix is redundant to quantify them, thus the full knowledge of the state is not required to accomplish the task. I reported the first protocol to measure the QC of an unknown state by means of a limited number of measurements, without performing the tomography of the state. My proposal has been implemented experimentally in a NMR (Nuclear Magnetic Resonance) setting.

In the final stage of the project, I explored the foundational and operational merits of QC. I showed that the QC shared by two subsystems yield a genuinely quantum kind of uncertainty on single local observables. The result is a promising evidence of the potential exploitability of separable (unentangled) states for quantum metrology in noisy conditions.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Adesso, G.
Guta, M.
Subjects: Q Science > QC Physics > QC170 Atomic physics. Constitution and properties of matter
Q Science > QA Mathematics
Faculties/Schools: UK Campuses > Faculty of Science > School of Mathematical Sciences
Item ID: 13397
Depositing User: EP, Services
Date Deposited: 25 Oct 2013 09:51
Last Modified: 20 Dec 2017 17:43
URI: https://eprints.nottingham.ac.uk/id/eprint/13397

Actions (Archive Staff Only)

Edit View Edit View