Optical properties of solid state emitters in structured environments

Abstract

Single photon sources (SPS) are a promising component for many quantum information
applications, where ideal properties include deterministic, highly efficient indistinguishable
emission, as this allows for near perfect two–photon interference. This thesis uses open
quantum systems theory to theoretically characterise solid state emitters; a class of single
photon sources which are deterministic in nature.
The main focus of this thesis is on the single molecule SPS dibenzoterrylene (DBT), a
photostable bright emitter when hosted in an anthracene nano–crystal.We present a theoretical
analysis of the temperature dependent optical properties of DBT, including the emission spectra;
where dephasing mechanisms which decohere emission and cause linewidth broadening
are underpinned. All observed spectral features are accounted for including, a zero phonon line
and discrete sharp peaks associated with transitions to local vibrational modes. Furthermore,
the model includes a thermal phonon bath, which allows for the inclusion of broad phonon
sidebands.
We present second order correlation function calculations for the DBT molecule where
both Hanbury Brown and Twiss and Hong–Ou–Mandel interferometer set ups are considered
under various driving regimes. In this work we present a novel method to extract photon
indistinguishability with experimental verification from a continuous wave laser measurement
and present results for driving the system with a pulsed laser.
We present a theoretical study of a DBT SPS coupled with different photonic structures. The
structures considered are optical filters and cavities; where a cavity QED master equation model
is developed which accounts for all DBT–anthracene spectral features. For both structures we
show novel predictions of collection efficiency and photon indistinguishability.
Finally, we present calculations of a NV center coupled to an ultrasmall–mode–volume
cavity. Where this work shows that indistinguishable photon extraction is possible at non–
cryogenic temperatures and is readily applicable to other deterministic emitters.

Date of Award	12 May 2022
Original language	English
Awarding Institution	The University of Bristol
Supervisor	Ruth Oulton (Supervisor) & Alex Clarke (Supervisor)