Nanoscale Quantum Optics

Traditional quantum optics studies light-matter interaction on length scales of an optical wavelength scale and larger. Metals and materials with loss are avoided as they may lead to unwanted decoherence. Recent progress in nanophotonics, plasmonics and metamaterials has shown that light can be strongly confined to scales much below the diffraction limit. The benefit of intense local fields may well outweigh the negative effects of dissipation, but one can ask whether standard quantum optics theory suffices on the subwavelength scale, and how well light fields can be controlled.

This workshop brought together experts from the different communities and discussed how quantum optics emerges on the nanoscale. The goal of the workshop was opened by Bert Hecht who presented an overview of nanophotonic scanning probe technologies and future plans to demonstrate quantum optics effects using plasmonics. This immediately led to active discussion that continued to the second day with a contribution from Almut Beige on quantum optics theory. This made the gap and difference in thinking between the more traditional quantum optics and the nanophotonics community very prominent. A number of promising nanophotonic systems were identified for which a complete quantum theory can be developed.

A number of these systems were addressed in the subsequent talks, from senior as well as junior scientists, which were all of very high level. Researchers working with quantum dots were brought up to date about studies of alternative quantum emitters such as NV centers, cold atoms, and vice versa. Promises and disadvantages of each of them became clear. As a common theoretical ground for all photonic media presented was the analysis of emission rates and other emitter properties in terms of the Green tensor of the media. Some junior PhD students among the participants were not yet familiar with the Green-function concept and they learnt quickly. As an experimental common ground, it serves to cite one participant who said that he had never been in a meeting where so many participants turned out to have done a Drexhage experiment (measuring how emission rates of quantum emitters vary as a function of distance to a mirror).   

Next to the stimulating scientific discussions and the very positive response from many participants, the workshop was definitely successful in presenting the Dutch nanophotonics and quantum optics community and in particular the FOM program on ‘Nanoscale Quantum Optics’ to the international community. This workshop could well be the first to establish a contact between international researchers from different disciplines that share an interest in quantum optics on the nanoscale.

The workshop benefited greatly from the active participation of the junior researchers. We believe this process was helped enormously by short, one-minute, presentations on the first day by each of the workshop participants. Once everyone’s background, research interests and expectations about the workshop had been expressed, people knew whom to team up with for scientific discussions from day one. It also worked quite well that all posters remained around us all week, so we had a permanent poster presentation that was also used as such.

Michiel de Dood (Leiden, The Netherlands)
Andrea Fiore (Eindhoven, The Netherlands)
Martijn Wubs (Copenhagen, Denmark)