## Ivan Fernandez Corbaton |
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Theory of Electromagnetic Scatterers Research Unit: Theoretical Nanooptics ivan fernandez-corbaton ∂kit edu |
Karlsruhe Institute of Technology (KIT) Institute of Nanotechnology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen, Germany |

# Research Project

I study the interaction between electromagnetic radiation and material systems by means of symmetries and conservation laws. In particular, I systematically employ the electromagnetic duality symmetry and its conserved quantity, the electromagnetic helicity. Their use allows to treat the electromagnetic polarization degrees of freedom in a straightforward way. This approach provides insights and/or design guidelines in diverse areas like zero backscattering, natural and artificial optical activity, metamaterials for transformation optics, nanophotonics phenomena involving the electromagnetic angular momentum and gravitational waves.

One example of my recent research is the definition of a measure that allows to quantify the electromagnetic chirality of an object https://journals.aps.org/prx/abstract/10.1103/PhysRevX.6.031013. The measure has an upper bound, and the objects that reach it have very extremal light-matter interaction properties: They are transparent to ALL electromagnetic fields of one of the two polarization handedness (helicity). This extremal behavior, which would be useful in many applications, is illustrated in the following figure.

Another example is a unified theory for describing conservation laws in light-matter interactions https://journals.aps.org/pra/abstract/10.1103/PhysRevA.95.053829. Among other things, it allows to obtain the optimal electromagnetic beam to transfer any measurable property from the field to a material system. For example, the following figure shows the transfer of linear momentum (left) and helicity (right) to the decorated sphere seen in the picture. The green dashed lines show the transfer achieved by a circularly polarized plane wave. The red lines show the transfer for the optimal beams.

Except for publications in journals that forbid it, my articles are publicly available on the arxiv

http://arxiv.org/find/physics/1/au:+Fernandez_Corbaton_I/0/1/0/all/0/1

and researchgate

https://www.researchgate.net/profile/Ivan_Fernandez-Corbaton/publications

where you can find the slides of some of my presentations as well.

My doctoral thesis is a monograph on the use of helicity and duality in light matter interactions:

http://arxiv.org/abs/1407.4432