Strong matter-light coupling with organic molecules and inorganic semiconductors
Abstract
This dissertation studies the effects of strong matter-light coupling on properties
of organic molecules and inorganic semiconductors. The interplay of
complex intramolecular dynamics and strong coupling of a photon to molecular
transitions results in new physics having no counterparts in other systems.
In contrast, low-energy optically active excitations of semiconductors (excitons)
usually do not feature such complexity. However, the combination of
strong electronic correlations and strong matter-light coupling leads to new
physics.
Firstly, the effect of strong coupling between molecular vibrations and
infrared photons on Raman scattering (RS) is considered. This is motivated by
the experiment of Ref. [1] showing up to 10³ enhancement of RS signal under
strong coupling. While the exact analytical results of this dissertation predict
around 100% enhancement of total RS signal, they cannot explain orders of
magnitude enhancement, leaving the question open for further studies.
Next, the effects of strong coupling of an optical photon and a molecular
electronic transition on molecular lasing properties are discussed. Starting
from a microscopic description of a driven-dissipative system, an exact (in the
thermodynamic limit) mean-field solution is developed. It allows to uncover
the mechanism of molecular lasing in the weak and strong coupling regime
and to obtain a non-equilibrium lasing phase diagram.
Finally, a semiconductor with different densities of electrons and holes,
strongly coupled to a microcavity photon, is studied. While finite electron-hole density imbalance is detrimental for excitonic condensation, it may still lead to a condensed state of excitons with finite centre of mass momentum
coexisting with unpaired electrons. On the other hand, due to its low mass,
a photon favours zero center of mass momentum condensation. The variational
mean-field calculations reveal that the interplay of these effects leads
to a variety of novel states with coexisting polariton condensate and unpaired
electrons.
Type
Thesis, PhD Doctor of Philosophy
Collections
Description of related resources
Strong matter-light coupling with organic molecules and inorganic semiconductors (thesis data) Strashko, A., University of St Andrews, 2020. DOI: https://doi.org/10.17630/e8d899d3-7c86-4919-8076-5e7ea746e5cfRelated resources
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