International Exchange Award: Quantum Networking with SnV Centres in Diamond

Niamh Mulholland outside the William-Eckhardt Research Centre at the University of Chicago

Niamh Mulholland, a PhD student from the University of Cambridge was awarded an M4QN international exchange award to visit the High Group at the University of Chicago. The visit took place in February 2026.

Cambridge-Chicago Collaboration: Quantum Networking with SnV Centres in Diamond

Niamh visited Professor Alex High’s group at the University of Chicago to strengthen an ongoing collaboration focused on developing diamond tin-vacancy (SnV) devices for quantum networking applications. The visit provided an opportunity to discuss shared scientific goals around scalable spin–photon interfaces, nanophotonic cavity design, and the material and fabrication challenges associated with integrating colour centres into high-performance photonic devices.

During the visit, Niamh met with members of the High Lab to discuss practical approaches for producing and processing diamond thin films with implanted SnV centres. This included discussions around sample preparation, materials quality, fabrication constraints, and how thin-film diamond platforms can be integrated into device structures for optical and quantum measurements. Niamh toured relevant laboratory facilities and gained insight into the group’s experimental approaches to quantum materials, nanophotonics, and device fabrication.

Benefits to the UK materials and quantum community

Tin-vacancy (SnV) centres in diamond are a promising platform for quantum networking because they can act as solid-state spin–photon interfaces, linking stationary spin qubits with optical photons that can transmit quantum information between distant nodes. Developing this platform requires both high-quality diamond materials and nanophotonic device structures that can efficiently interface SnV centres with light.

This visit benefited the UK materials and quantum community by strengthening an international collaboration that brings together complementary expertise. Professor Alex High’s group has strong expertise in diamond thin-film processing, nanophotonic device fabrication, and quantum materials, while the group at Cambridge contributes expertise in optical measurements.

This exchange helped connect materials development directly with device-level and measurement requirements, ensuring that fabrication approaches are guided by the needs of future quantum experiments. The visit fits closely with the aims of M4QN by supporting interdisciplinary and international collaboration, and by addressing the materials and device challenges needed to build scalable quantum networks.

Visit Outcomes

Overall, the visit was valuable for building a stronger collaborative relationship, exchanging technical knowledge, and aligning future research directions.

Specifically, the visit clarified practical next steps for the sample collaboration, including approaches to sample preparation, processing, and characterisation. It also enabled direct knowledge exchange on fabrication methods, materials processing constraints, and the requirements for integrating diamond thin films into nanophotonic structures.