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

TL;DR

This study examines how silicon-vacancy and germanium-vacancy centers in nanodiamonds shift their optical emission lines under pressures up to 180 GPa, supporting their potential for quantum sensing in extreme environments.

Contribution

It provides experimental data and ab initio calculations on pressure-induced shifts of SiV and GeV centers, extending understanding to high-pressure regimes up to 180 GPa.

Findings

SiV zero-phonon line shifts by 17 THz under pressure

GeV zero-phonon line shifts by 78 THz under pressure

Results align with theoretical lattice compression models

Abstract

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 synthetized 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 blue-shifts 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.