Transformation optics for nanoantennas and quantum emitters

An unprecedented research effort in nanophotonics and nanoplasmonics has been directed toward fabrication and characterization advancements. Very complex structures have been realized experimentally and their properties are routinely measured. From these experiments scientists have gained significant insight on the physics at the nanoscale. Nevertheless, nanophotonics and nanoplasmonics rely strongly on cumbersome simulations for both, the design and modelling of the experiments, which may not reveal in simple terms all the underlying physics. Comprehensive understanding can only be achieved via analytical approaches. Beside, analytical solutions can potentially speed up the design procedure.

To tackle the challenge of modelling analytically complex scenarios, the PhD student will look at the technique known as transformation optics, which has been used successfully in metamaterials for invisibility [1]. In the frame of nanophotonics and nanoplasmonics, it has been shown that this technique can remove the complexity of today’s complex nano-scenarios through a spatial transformation, reducing the problem to one that may be solved analytically.

The PhD initial goal will be to extend the existing classical analytical model for bowtie nanoantennas [2] to other nanoantennas and nanocavities. Particular attention will be given to study the strong coupling regime whereby a quantum emitter (such as dye molecules and quantum dots) coherently exchange energy with the plasmonic modes supported by the metallic nanoantennas. The PhD will subsequently incorporate quantum effects that are not accounted for yet, such as quantum tunnelling. To this end, a semi-classical approach will be followed in the first instance and models from cavity quantum electrodynamics will be adopted.

We expect the PhD candidate to develop the expertise required to lead a theoretical research project involving analytical and simulation work, to train students and to interact with colleagues with different backgrounds (physics and engineering). Further details of the project will be agreed with the interested candidates to tailor the research on his/her interests.

The research programme will take place in an international and interdisciplinary environment, which will substantially favour collaboration opportunities 1) within the School of Physics and Astronomy (Prof. Shuang Zhang and Dr. Jensen Li), and 2) within other research institutions (King’s College London, UK; Universidad Autónoma de Madrid, Spain; Nanyang Technological University, Singapore).