High dimensional spatial entanglement with photon pairs

This work is a theoretical investigation of the process of spontaneous parametric down-conversion, which consists in pumping a crystal with a laser to create entangled pairs of photons. In particular, it is an investigation of the properties of the entangled pairs that are created and on how their entanglement can be measured. We approach some of these questions both analytically and numerically. The work is divided in three parts. The first is an introductory part, that consists of three chapters in which we set the framework and give the tools that are needed to understand the rest of the work. The second part consists of two chapters and it is concerned with the bi-photon states that are generated in downconversion, in particular it approaches the problem of quantifying the amount of entanglement that those pairs carry and to understand on what parameters it depends in an analytical (chapter 4, based on the paper EPJD 66 (7) 183 (2012)) and a numerical way (chapter 5, based on the paper "Spatial Schmidt modes in parametric down-conversion", submitted to EPJD, in press (2012)). The numerical approach allows to overcome all the approximations previously employed. We will learn that the strength of the entanglement depends on quantities such as the size of the crystal, the size of the pump and the phase mismatch between the photons. The third part is written over three chapters and it is concerned with detecting the entangled pairs in a way that exposes the highest amount of entanglement possible. Various strategies will be analysed, ranging from projective measurements (chapter 6, based on the paper Physical Review A 83, 033816 (2011), and chapter 7, based on the paper EPJD 66 (7), 178 (2012)), to the use phase masks (chapter 8, based on the paper New J. Phys. 14, 073046 (2012) and on my master thesis [1]). We will learn that in certain situations, the most common approximations found in literature can be quite restrictive and we address the problem of understanding under what conditions they could or shouldn't be used. The thesis ends with chapter 9, which is a resumé of the work, and an outlook to future developments, which then blurs into the acknowledgments.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

2012

Author dc:creator

• Miatto, Filippo M.

DOI

10.48730/0j6x-tg34

Identifier

T13382

OAI identifier oai:identifier

oai:strathclyde:bn999675p