PhD defence by Emil Vosmar Denning

Title:  Quantum photonics in structured environments


Principal supervisor: Professor Jesper Mørk, DTU Fotonics Engineering, Denmark
Co-supervisor: Professor Morten Willatzen, DTU Fotonics Engineering, Denmark
Co-supervisor: Dr. Jacob Christian Iles-Smith, University of Manchester, UK

Evaluation Board
Associate Professor Martijn Wubs, DTU Fotonics Engineering, Denmark
Professor Richard Warburton, University of Basel, Switzerland
Professor Klaus Mølmer, Aarhus University, Denmark

Master of the Ceremony
Associate Professor Søren Stobbe, DTU Fotonik

This PhD project investigates the interaction of light and matter in semiconductor nanostructures. The primary objects of the study are man-made 'artificial atoms' that can be grown on a chip – quantum emitters. These quantum emitters can be operated as light sources that emit a single photon at a time. By encoding information into the photons, these can then play the role as quantum bits in a quantum computer or transmit information in a quantum communication scheme. A significant challenge in such implementations is posed by vibrations in the solid state material constituting the emitter and its surroundings. The impact of these vibrations on the properties of light generated from an emitter is a key element of the PhD project. By structuring the environment on the chip around an emitter, one can enhance its interaction with light, thereby improving control of the emitter. This principle allows to suppress the impact from vibrational dynamics on the emitted photons and has extensively been studied in the project.

Besides from generating single photons, the emitter itself can also be used for carrying quantum information and thereby play the role of a quantum bit. This can be realised by trapping a single electron in the emitter, effectuated by placing electrical contacts around it. In this case, an important effect arises from the interaction between the single electron and the nuclei from the solid state material surrounding it. In analogy with the vibrational modes, these nuclei can act as a noise source that washes away the information contained in the emitter on a short time scale. However, in this project, it has been investigated how the nuclei can be turned into a resource. In particular, it has been studied how the nuclei can be operated coherently to store the state of the electron, thereby acting as a memory unit that can be used in quantum computation and communication schemes.


Wed 11 Mar 20
13:30 - 16:30


Lyngby Campus
Building 341, auditorium 23