Lab exchange grant: Photonic characterisation of engineered epitaxial quantum dots

Members of the Integrated Quantum Photonics Lab at the University of Cambridge. From left to right: James, Mehdi, Yonatan, Steven, Yuting, and Solomon.

Mehdi Ahmadian, a PhD student at The University of Manchester was awarded an M4QN laboratory exchange award to visit Dr. Luca Sapienza at The University of Cambridge from 9-13 March 2026.

The purpose of the visit

The primary objective of this exchange was to perform advanced optical characterisation of III-V epitaxial quantum dots (QDs) that had undergone specific engineering processes at the University of Manchester. By leveraging the specialised facilities at The University of Cambridge’s Integrated Quantum Photonics Lab, the visit aimed to investigate how these engineering modifications influenced the photonic properties of the QDs.

A key technical focus was using low-temperature micro-photoluminescence spectroscopy to map the emission spectra of local QDs across various regions of the sample. Additionally, the visit sought to conduct lifetime measurements to gain deeper insights into the carrier dynamics of these engineered nanostructures, providing a data-driven foundation for future quantum device fabrication.

Benefits to the UK materials and quantum community

This visit fostered synergy between two leading UK research hubs: the Photon Science Institute at Manchester and the Nanoscience Centre at Cambridge. By sharing institutional capabilities and technical expertise, the exchange facilitated a more integrated approach to quantum materials research in the UK.

For the broader UK materials and quantum communities, this collaboration contributed to the development of high-performance quantum light sources, which are essential components for quantum communication and sensing. Furthermore, the exchange provided a vital professional development opportunity for Mehdi, an Early Career Researcher (ECR). By engaging with Cambridge’s experts, Mehdi gained unique insights into state-of-the-art characterisation techniques and expanded their professional network, ensuring that high-level technical knowledge remains and grows within the UK quantum ecosystem.

Visit outcomes

The visit yielded several significant outcomes:

– Technical Data: low-temperature micro-photoluminescence spectra and lifetime measurement data for the engineered QDs were successfully obtained. These results provide a clear picture of how our engineering processes affect the QDs’ photonic performance.

– Established Collaboration: The visit formalised a working relationship between The University of Manchester and The University of Cambridge. This was reinforced by multiple strategy meetings where we discussed results, shared capabilities and mapped out future research directions.

– Ongoing Research: Demonstrating the success of the exchange, the host group has kept the samples in Cambridge for additional characterisation. Follow-up discussions are being planned to analyse the final data set and decide on the next stages of our joint quantum dot experiments.

– Knowledge Exchange: The visit enabled a two-way sharing of laboratory best practices and characterisation methodologies, which will benefit the research workflows of both participating groups.