College of Science & Engineering

Portable Quantum Device for (Q-)Chirality Measurements

Supervisor: Dr Sara Restuccia and Dr Joe Knapper

School: Physics & Astronomy

Description: 

Optical activity is a macroscopic property of chiral molecules, which manifests as a rotation of linear polarization when light passes through a sample. Traditionally, the optical activity of a material is tested by studying the interaction of a linearly polarised beam of light with the sample through a measurable rotation in the polarisation of the transmitted light. Chirality is essential information in many fields, including drug development, where the wrong chirality can render a drug ineffective or toxic. Crucially, in classical detection, the precision of the measurement increases with the intensity of the incident light. However, higher intensity increases the risk of damaging the sample. Low light quantum detection systems are key to eliminating these risks. In recent publications, Dr Restuccia proposed and tested a novel quantum polarimetry system. In contrast to classical polarimetry methods and existing low light systems, the proposed method uses non-polarised light. Detection is based on a Bell-type inequality configuration that can measure the chirality of a molecule in solution in the single photon regime, and able to probe the optical rotation of a chiral solution using non-polarised light.

We propose designing and producing a portable quantum device based on this configuration. The portability, allowing greater applications and broader use, will be achieved by 3D printing smaller, lighter, low-cost optical mounts. Where misalignment is caused by transportation, a closed-loop self-alignment step will be developed. This lowers the barriers to entry for quantum sensing of
chirality, as the system will require a lower budget and less manual alignment, allowing new users to quickly become trained on the apparatus. This is crucial in allowing the research to be developed for its use by a broad, multidisciplinary audience.

The project is structured in 4 stages:

1) Literature review: The student will obtain a literature-based understanding of Bell-experiments for precision measurements and existing polarimetry detection.

2) Experience on a working system: Align and use a lab-based Bell experiment for chiral measurements, giving an understanding of the quantum system and allowing them to replicate published results.

3) Develop a 3D-printed version of the system.

4) Reproduce the results achieved in step 2 with the new designed set-up.

This project will require familiarity with the standard Bell inequality system, as well as confidence in 3D printing and automated instrumentation. The output of this project will be a more broadly applicable Q-chirality system, with open-access designs, lowering barriers to a fundamental quantum-sensing technology.