Researchers at The City College of New York demonstrated how a quantum emitter, the nitrogen-vacancy (NV) center in diamond, interacts unexpectedly with a specifically built photonic structure when moved with a scanning needle. The study, “Emission of Nitrogen-Vacancy Centres in Diamond Shaped by Topological Photonic Waveguide Modes,” was directed by Carlos A. Meriles, Martin and Michele Cohen Professor of Physics in the Division of Science, and is published in the journal Nature Nanotechnology.
An NV-hosting nanodiamond on an AFM tip probes a topological waveguide. Suppressing RCP emission at 710 nm reveals regions supporting chiral modes. (fringes in right image). Image Credit: The City College of New York
The NV center’s broad and messy emission spectrum, once seen as a disadvantage, has now been found to enable a new kind of interaction that reshapes its light in ways not previously observed. This discovery is especially important for quantum information technology, as it could help address long-standing challenges like spectral diffusion and open the door to reliable spin-photon and spin-spin entanglement directly on a chip.
At the same time, the study displays a unique sensing capability: by evaluating the NV emission, the team was able to reconstruct precise, polarization-resolved pictures of the photonic modes with high contrast.
Beyond photonic structures, this polarization sensitivity could eventually be applied to detecting chiral molecules, which are central to biology and medicine.
Carlos A. Meriles, Study Lead, The City College of New York
Meriles stated that future research would go in both directions, studying quantum emitter-structure interactions further and inventing novel sensing applications based on the same concepts.
Journal Reference:
Kumar, R., et al. (2025) Emission of nitrogen–vacancy centers in diamond shaped by topological photonic waveguide modes. Nature Nanotechnology. doi.org/10.1038/s41565-025-02001-3