Photonic-cavity-enhanced laser writing of color centers in diamond

Nano Letters (2024)

 

Color centers in diamonds are defects in the diamond structure that are useful in quantum technologies, such as quantum computing and sensing. However, creating these color centers is currently a random process. If scientists could create them in a deterministic way, it would improve the production and scalability of quantum devices made from diamonds.

In this paper, researchers have extended a process known as laser-writing, where focused laser pulses are used to create defects in diamonds. This method had previously shown success in creating defects in bulk diamond.

They applied the laser-writing process to tiny diamond structures, such as nanopillars and photonic resonators, which are etched into thin diamond membranes. These devices can control light at very small scales.

The researchers successfully created carbon vacancy centers and nitrogen vacancy centers in the nanophotonic devices. They saw improved photoluminescence. They also used special structures called bullseye resonators, which focused the laser energy more efficiently. This allowed them to create defects with much lower energy than usual—100 times less energy than typically needed in larger diamonds.

The authors of this result are Anchita Addhya, Victor T., Xinghan G., Ian Hammock, Zixi Li, Melody L., Clayton DeVault, David Awschalom, Nazar Delegan, F. Joseph Heremans and Alex High, who conducted their work at the University of Chicago and Argonne National Laboratory.