Spin-strain coupling in nanodiamonds as a unique cluster identifier

Fluorescent nanodiamonds have been used to a large extent in various biological systems due their robust nature, inert properties and the relative ease of modifying surface for attachment different functional groups. Within given batch, however, each nanodiamond is indistinguishable from its neighbors so far one could only rely on fluorescence statistics some global information about ensemble. Here, we propose measure possibility adding another layer unique information, relying coupling between strain spin degree-of-freedom nitrogen-vacancy center diamond. We show that variance axial transverse can be encoded an individual radio-frequency identity cluster nanodiamonds. When using single nanodiamonds, this fingerprint then potentially tracked real-time in, e.g., cells, as size compatible with metabolism intake. From completely aspect, clusters already now serve platform anti-counterfeiting measures.