Diamond–Photonics Interfaces for Quantum Sensing

Diamond is widely recognized as a promising solid-state platform for quantum technologies, owing in particular to the versatile properties of its nitrogen-vacancy (NV) centers. These atomic-scale defects enable highly sensitive measurements of magnetic and electric fields, temperature, and strain. Among these functionalities, NV-based magnetometry stands out for its exceptional sensitivity under ambient conditions, without the need for cryogenic operation. Nevertheless, current NV magnetometers rely on bulky free-space optical setups for excitation and photoluminescence collection, which limits scalability, stability, and integration into compact devices.

This PhD project aims to address these challenges by developing chip-scale quantum magnetometers that combine bulk diamond with advanced photonic architectures. The central vision is to engineer efficient excitation and collection pathways for NV centers directly through integrated waveguides and flat-optical couplers, thereby overcoming the bottlenecks of traditional free-space approaches. Such integration will enable compact, robust, and scalable devices while maintaining—or even enhancing—the exquisite sensitivity of NV-based sensing.

The research will span several interconnected domains. On the design side, the candidate will explore novel nanophotonic structures that maximize the interaction between guided light and NV centers, leveraging inverse design techniques, metasurfaces, and flat-optics interfaces to tailor excitation and collection pathways. On the materials side, the project will involve engineering high-quality diamond samples and optimizing their integration with photonic integrated circuits (PICs). On the experimental side, the candidate will perform optical measurements to characterize device performance, benchmarking sensitivity, spatial resolution, and stability against the state of the art.

Through this multidisciplinary effort, the project will provide the candidate with hands-on expertise at the intersection of quantum sensing, integrated photonics, and flat optics. The anticipated outcome is a scalable platform for high-resolution magnetic field imaging that surpasses current benchmarks in both sensitivity and miniaturization. Such a platform will open new opportunities for probing condensed matter systems, characterizing advanced materials, and enabling practical quantum devices for a range of scientific and technological applications.