Optical properties of SiV and GeV color centers in nanodiamonds under hydrostatic pressures up to 180 GPa

We investigate the optical properties of silicon-vacancy (SiV) and germanium-vacancy (GeV) color centers in nanodiamonds under hydrostatic pressure up to 180 GPa. The nanodiamonds were synthesized by Si-or Ge-doped plasma-assisted chemical vapor deposition and, for our experiment, pressurized in a diamond anvil cell. Under hydrostatic pressure we observe blueshifts of the SiV and GeV zero-phonon lines by 17 THz (70 meV) and 78 THz (320 meV), respectively. These measured pressure-induced shifts are in good agreement with ab initio calculations that take into account the lattice compression based on the equation of state of diamond and that are extended to the case of the tin-vacancy (SnV) center. This work provides guidance on the use of group-IV-vacancy centers as quantum sensors under extreme pressures that will exploit their specific optical and spin properties induced by their intrinsic inversion-symmetric structure.

Automated summary

In this study, we investigate the optical properties of silicon-vacancy (SiV) and germanium-vacancy (GeV) color centers in nanodiamonds under high pressures. We observe blueshifts in their spectra, and these shifts are in good agreement with ab initio calculations considering the lattice compression. This research provides guidance for using group-IV-vacancy centers as quantum sensors with specific optical and spin properties under extreme pressures.