Chiral Induction from Microns to Electrons for Radiative Anisotropy – CHIMERA

The project will explore how organized assemblies of helical objects can give rise to a supramolecular response that can result in the induction of chirality from the helices to fundamental particles such as photons or electrons. This will represent an unprecedented leap in the understanding of how chirality at the macroscopic scale can affect matter over multiple length scales. We hypothesize that substrates decorated with organized helical assemblies are conducive to induce spin selectivity of coherent UV light emitted upon excitation in the mid-IR. To control the range of applicable wavelengths, which should ideally be in the UV-Vis range for most applications, we will target chiral objects 10 – 100nm in size. To this end, we have devised a novel synthetic strategy in which a soft helical template with controlled handedness (right vs left handed) and pitch is used to fabricate a hard, helical outer shell containing nanometric chiral information (pitch and length) from tens to hundreds of nanometers. Then, this outer shell is used to template the pyrolysis or polymerization of the encapsulated organic matter to generate twisted graphenoid nano-dots (C-dot). Preliminary results demonstrate the effectiveness of this unprecedented approach, which yields C-dos exhibiting induced chiroptical properties resulting from the induction of chirality from the original organic template to the silica shell, and then onward to the C-dot's electronic orbitals.
The objectives of the project are the preparation of stable, emissive chiral carbon materials composed of extended p-congugated nano-domains. We will investigate the chiroptical properties induced by their chiral structure, and these results can be used to tune the coherent femtosecond emission of UV to deep UV photons produced by non-linear processes. To reach these objectives, we will prepare graphenoid nanohelices designed to produce giant (possibly nonlinear), tunable optical activity. To expand on the intrinsic properties of the C-dots, we will incorporate heteroatoms or aromatic molecules inside the supramolecular architecture during the double template synthesis to obtain doped with the aim of further tuning their chiroptical properties.
Beyond these first tangible deliverables, we will also aim for high-gain objectives such as investigating how the nanostructure can couple the spin and orbital angular momentum of light. Indeed, the emission angle, intensity, twisted wavefronts, and spin angular momenta of UV-emission will depend drastically on the global symmetry, non-local order, and density of the helically arranged C-dots. In order to see the emergence of coherence at the mesoscopic scale and enhance a collective non-linear response, we will also tackle the challenging arrangement of the helices relative to each other.
The project's goals are mostly fundamental, but we aim to bring this technology from TRL 1 to TRL 3-4. Successful completion of this research will broaden perspectives in the fields of optoelectronics by providing new circularly polarized photoluminescent hybrid materials for inclusion into multi-dimensional matrices. Possible applications include generating high energy UV light from mid-IR sources through HHG processes. Our approach will further allow the fabrication of sources with controllable circular polarization, which potentially represents a huge gain.