Light-Matter Interactions in Complex Systems – Dr Cyriaque Genet

A blend of concepts leads us to explore how complex systems interact with tailored light and to reveal new phenomena in contexts ranging from chiral light-matter coupling, stochastic thermodynamics, and quantum materials.

We exploit different approaches ranging from polarization optics, optical forces, chiroptical spectroscopies, supramolecular chemistry, etc. to reveal new interaction regimes where chiral coupling and fluctuations play a central role.

Our research aims at harvesting them to drive, resolve and optimize chiral systems.

1. In close collaboration with T.W. Ebbesen, we have been engaged in revealing and understanding how chemistry can be modified in the `vacuum field’ strong light-matter coupling regime. In this context, we have been studying closely the different coupling mechanisms that are at play when molecular transitions and vibrations are coupled to cavity modes, for both collective and cooperative regimes. We have been interested in the crucial role played by molecular symmetries. This guided us to study the use of chiral coupling for engineering new polaritonic quantum systems in chiral optical cavities and two-dimensional materials and to reveal new cavity protection mechanisms.
2. We are also studying the progressive emergence of chirality on complex, self-assembled, supramolecular systems. We have been developing polarimetric tools well adapted to such questions and systems by setting up Mueller microscopes. Such tools have enabled us for instance to promote Frenkel exciton strong coupling as a route for enhancing chiroptical signatures. We are currently developing a 2-dimensional `action spectra’ Mueller polarimetry focusing on the close but complex relation between supramolecular symmetries and circularly polarized luminescence effects.
3. Chiral light-matter interactions can also be approached from the perspectives of optical forces. We have demonstrated new types of optical forces that solely engage the chiral content of the light field with the chirality of matter. Such forces lead to a new thermodynamics where chiral degrees of freedom are transformed into true thermodynamic parameters. The crucial role played here by thermal fluctuations made us enter the field of stochastic thermodynamics and bath engineering. We are also implementing optical trapping protocols for emulating quantum phenomena to understand to which extend the ‘quantum’ can become a resource for stochastic energetics.

Fundings : QMat, CSC, USIAS, PRC ANR, CEFIPRA