Deterministic coupling of Quantum Dot mechano-excitons to high-Q SAW-cavity modes

Research Topic

The interaction between optical, electronic, and vibrational modes can be strongly enhanced by confining them to a small volume. Such enhanced interactions give rise to the celebrated Purcell effect which has been studied in the optical domain for many years. In this project, we aim to shift this paradigm to the phononic domain by replacing (optical) photons with SAW-phonons.


Goals

The main goal of this project is the demonstration strong optomechanical coupling between quantum dot (QD) excitons and localized pho¬non fields. To enhance interactions between these mechano-excitons and the SAW, thin semiconductor membranes containing a layer of QDs have to be hybridized with high-Q SAW cavities on strong piezoelectric substrates using the technique of epitaxial lift-off and transfer.
The first part of the project was focused on the fabrication of such hybrid QD-LiNbO3 devices and to study the propagation of the SAW inside the QD membrane transferred onto a basic LiNbO3 delay line / resonator device. This achievement completes the first scientific Milestone of this project. We also submitted a manuscript reporting on our successes. A preprint of the submitted manuscript is already available online at https://arxiv.org/abs/1705.09948.
Currently, we are advancing this design to interface single quantum dots with high-Q SAW resonator modes. We hope that with these devices, we will achieve the ultimate goal of this project to demonstrate strong sound-matter coupling.

Fellow

Emeline Nysten

Host: Universität Augsburg – Institut für Physik

Scientific Background

I am an engineer in materials science and chemistry with a double diploma from the Augsburg Universität (Germany) and the Université catholique de Louvain (Belgium). My main focus are solid state physics and materials science, more specifically the fabrication and characterisation of nanostructures. In my master thesis, I worked with hybrid multiferroic nanocomposites composed of ferroelectric polymer and ferromagnetic nanotubes.