13 October 2014 Congratulations to New ICFO PhD graduate

Thesis Committee

Dr. Christin David graduated with a thesis in ‘Nonlocal and Collective Phenomena in the Plasmons of Metallic Nanostructures’ Dr. Christin David received her Diploma in Physics from the Berlin University of Technology, Germany, before joining the Nanophotonics theory research group led by ICREA Professor at ICFO Javier García de Abajo. She centered her doctoral work at the Universidad de Autónoma de Madrid on nonlocal plasmonic response of the free electron gas in metal nanostructures, and on the interactions of light with particle arrays. Dr. David’s thesis entitled ‘Nonlocal and Collective Phenomena in the Plasmons of Metallic Nanostructures’ was supervised by Prof. Javier García de Abajo.


Light-matter interaction in nanophotonics involves processes within the electron subsystem in solids. Dealing with nanosized metal structures makes it necessary to account for the quantum nature of electrons. This leads to additional damping and compromises idealized optical concepts, since plasmon resonances are broadened, undergo strong frequency shifts and become attenuated. The present thesis aims to understand the physics of such nonlocal effects by finding the limiting regimes of structural parameters in plasmonic devices in which the commonly used local approximation may break down. Nonlocal effects are analyzed in the optical field enhancement underlying a number of spectroscopical methods.

Optical phenomena based on collective effects in nanoparticle arrays are discussed. They have the ability of strongly confining photons in all dimensions at the edge of band gaps yielding strong local field enhancements. In particular, 3rd generation solar cells benefit from the combined use of collective effects in novel photoactive layers. Nanoparticle assisted absorption enhancement is for instance compatible with the employment of photoluminescent nanocrystals, used for downshifting the incident light to energies close to the bandgap of Si. In this context, a very modest increase in efficiency with low cost increase can have dramatic consequences towards the solution of energetic and environmental problems of our society.

Thesis Committee:

Prof. Francisco Meseguer – Universidad Politécnica de Valencia
Prof. Juan José Saénz – Universidad Autónoma de Madrid
Prof. Tobias Stauber – Universidad Autónoma de Madrid
Prof. Martijn Wubs – Technical University of Denmark
Dr. James Connolly – Universidad Politécnica de Valencia