PhD defence by Maria Vittoria Gurrieri

Abstract

This work studies the interaction between light and matter at the nanoscale with a view to advancing quantum technologies. As our world becomes increasingly data-driven, there is a growing need for energy-efficient methods of information transmission. Optical interconnects, instead of the traditional electrical ones, represent a promising solution, but the development of efficient systems for generating and detecting light is a crucial step, particularly given the limitations of traditional silicon chips in emitting light.

Nanophotonics, the study of light at the nanoscale, is a key area of research to address these challenges. The objective of this work is to study the interaction between light confined in an optical nanocavity and the matter excitations of a 2D material. Our research reveals the circumstances under which this system can generate coherent light with lower energy demands than traditional lasers. Our findings demonstrate the significant influence of temperature and optical field confinement on this behaviour.

The second objective of this research is to evaluate the efficacy of methodologies for simplifying quantum correlations within a system. Given the complexity of quantum mechanics, it is impractical to account for all the correlations within a system. Therefore, it is crucial to determine when simplifications can be made without compromising accuracy.
To this end, we evaluate the quantum cumulant expansion as a technique for simplifying the study of the emission spectrum in our system. This approach is used to manage higher-order correlations, thereby facilitating the investigation of challenging quantum systems. We show the limitations of this method, particularly in the presence of strong nonlinear effects, to ensure the reliability of our predictions.

Supervisors

• Principal supervisor: Professor Jesper Mørk, DTU Electro, Denmark
• Co-supervisor: Senior Researcher Philip Trøst Kristensen, DTU Electro, Denmark
• Co-supervisor: Dr. Kristín Björg Arnardottír, University of Southern Denmark, Denmark

Evaluation Board

• Associate Professor Nicolas C. Leitherer-Stenger, DTU Electro, Denmark
• Tenured researcher Fabrice Laussy, The Material Science Institute of Madrid, Spain
• Professor N. Asger Mortensen, University of Southern Denmark, Denmark

Master of the Ceremony

• Senior researcher Thomas Christensen, DTU Electro, Denmark