UV laser pulses selectively modify diamond defects while preserving qubits
Researchers tested 266-nanometer ultraviolet laser pulses on single-crystal CVD diamond to alter atomic-scale defects in localized regions. The approach aimed to control specific defect populations without disrupting nearby nitrogen-vacancy centers used as quantum bits. The work was published in Diamond and Related Materials.
The study focused on a single-crystal diamond grown by chemical vapor deposition. Researchers delivered 266-nanometer ultraviolet pulses lasting only a few nanoseconds to small areas, aiming to change selected atomic-scale defects through localized optical excitation rather than bulk heating.
Before irradiation, the team mapped the untreated crystal with confocal photoluminescence, ultraviolet-visible absorption, and Fourier-transform infrared spectroscopy. These measurements documented the starting defect landscape, optical transparency, and impurity levels, including very low substitutional nitrogen compared with nitrogen-rich diamond. Two-dimensional photoluminescence maps tracked the 563-nanometer center's zero-phonon-line intensity after irradiation.
This work may influence quantum-device researchers and sensor developers by suggesting a route to tune diamond defects locally while retaining nearby NV qubits. If such control proves reliable, it could support more precise magnetic or electric field sensing and help advance diamond-based quantum hardware. Broader benefits would depend on reproducibility, scalability, and whether the method avoids unwanted damage in practical devices.