Researchers have engineered and fabricated new diamond phononic crystals which could be used to control the interactions between high frequency phonons and solid-state quantum systems, unlocking new potential controls to mitigate the effects of vibrations in these systems.
Their work, which is published in Nature Physics, involved both designing and fabricating the new diamond-based phononic crystals with embedded silicon-vacancy color centers at nanoscale precision. When using the crystals, the team noted an 18-fold decrease in the orbital relaxation rate, demonstrating the crystals ability to suppress photon processes.
"One of the most difficult parts of this study was the fabrication of phononic crystals in diamond," said Kazuhiro Kuruma, first author of the paper. "We carefully optimized a diamond etching process to fabricate these crystals with very small features down to 20 nm into single crystal diamond."
Notably, the team discovered that when using the new diamond phononic crystals, the interactions between single phonons and quantum emitters could be suppressed at temperatures up to 20K.
"We demonstrated phononic crystals that can suppress high-frequency phonons from 50 to 70 GHz," Kuruma added. "In addition, we demonstrated that spontaneous single-phonon processes in single quantum systems are suppressed by the phononic crystals even when increasing temperatures up to 20 K."
The findings, and new phononic crystals, could create pathways for advanced quantum technology development employing reliable control of phonon interactions.