Quantum-Grade Nanodiamonds from a Single-Step, Industrial-Scale Pressure and Temperature Process

Abstract

Nanodiamonds with nitrogen vacancy (NV) centers are a promising workhorse for myriad applications, from quantum sensing to bioimaging. However, despite two decades of extensive research, their use remains limited by the lack of scalable methods to produce quantum-grade material. While traditional NV-production methods involve multi-step irradiation and annealing processes, a fundamentally different approach is presented here based on a single-step high-temperature plastic deformation. It enables industrial-scale yield of high-quality luminescent nanodiamonds while significantly reducing production time and costs. Utilizing a unique cubic press apparatus capable of reaching higher temperatures and pressures, 50-nm luminescent nanodiamonds with outstanding optical and spin properties are achieved in a single step from non-luminescent material. Compared to electron-irradiated nanodiamonds, i.e., common commercially available material, this method yields NV centers with significantly improved charge stability, T1 relaxation times approaching 1 ms, and a approximate to 5-fold enhancement in optical Rabi contrast. What this streamlined process produces in one week would require more than 40 years by current irradiation and annealing methods. Scalable, quantum-grade nanodiamonds are thus unlocked, providing the missing link for their widespread adoption.