TopROCS: Topologically protected chiral sensing

Chiral molecules of opposite handedness are indistinguishable when they interact with a mirror-symmetric object, but have

dramatically different responses when they interact with another chiral object. Chiral sensing methods are of paramount importance

in fundamental science, from chemistry to biology and physics, as well as in industrial sectors such as the pharmaceutical industry.

Amongst these methods, all-optical ones like optical rotation are well established and easy to use, but are limited by very low signals and are also affected by experimental noise.

In this project, I aim to develop the theory for new all-optical chiral sensing methods that are highly efficient, highly sensitive and

robust against noise. To achieve efficiency and sensitivity, I will use synthetic chiral light (SCL), a new type of light that produces

unprecedently strong enantiosensitive signals by encoding its handedness in the temporal evolution of the electric-field vector of the

light. To provide noise robustness, I will extend the concept of SCL and create chiral topological light (CTL), that is, SCL with a spatial

distribution of handedness with non-trivial topological properties. By transferring the CTL topology onto the molecular response, I

will enable the observation of novel chiral observables that are robust against noise owing to their topological nature. Additionally, I

will use SCL to modulate the coupling toward the environment of an ensemble of chiral molecules, inducing exceptional points (EPs)

and harnessing EP-related effects such as topological population transfer in an enantiosensitive way. Finally, I will devise a sensor for

chiral detection based on optical fibres that will be tuned to an EP and interact with a surrounding medium via SCL, paving the way for a new generation of chiral sensors.