Control of photon emission from single molecules and planar materials

Abstract

Optical quantum technologies are considered a key focus of contemporary scientific research, offering a fascinating potential of redefining many of the traditional boundaries of human activities. Such systems, however, can only emerge as complete practical tools if some necessary conditions are satisfied. One of these prerequisites is the ability to generate photons that appear identical regarding all their optical traits, a condition simply called indistinguishability. In essence, this also mandates an adequate control over the spectral centre of such particles. Hence, developing methods of appropriately generating and processing photons are a necessary requirement for any successful realisation of optical quantum technologies.

In this thesis I made several steps forward in this direction. The first chapter contains an introduction to all the foundation concepts that are necessary for the experimental and theoretical investigations that follow. The second chapter consists of a novel experimental demonstration of strain as a spectral tuning mechanism for photons emitted by dibenzoterrylene molecules embedded inside anthracene crystals. This is accompanied by a theoretical simulation of that effect which is based on molecular dynamics and density functional theory. The third chapter is dedicated to a theoretical analysis of a novel setup that relies on encapsulating a plasmonic nanoresonator within a dielectric cavity in order to achieve indistinguishability at room temperature via cavity funneling effects. In the fourth chapter I present an experimental implementation of room temperature single photon sources that are based on hexagonal boron nitride with two different techniques being used for the activation of the underlying emitters. Finally, the fifth and last chapter contains a general overview along with all the conclusions that have been derived within this thesis and some potential extensions that could be attempted in the future.

Date of Award	13 May 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Dara McCutcheon (Supervisor) & Alex S Clark (Supervisor)