Photoluminescence excitation spectroscopy of SiV⁻and GeV⁻color center in diamond

Abstract

Color centers in diamond are important quantum emitters for a broad range of applications ranging from quantum sensing to quantum optics. Understanding the internal energy level structure is of fundamental importance for future applications. We experimentally investigate the level structure of an ensemble of few negatively charged silicon-vacancy (SiV − ) and germanium-vacancy (GeV − ) centers in bulk diamond at room temperature by photoluminescence (PL) and excitation (PLE) spectroscopy over a broad wavelength range from 460 nm to 650 nm and perform power-dependent saturation measurements. For SiV − our experimental results confirm the presence of a higher energy transition at ∼ 2.31 eV. By comparison with detailed theoretical simulations of the imaginary dielectric function we interpret the transition as a dipoleallowed transition from 2 E g -state to 2 A 2u -state where the corresponding a 2u -level lies deeply inside the diamond valence band. Therefore, the transition is broadened by the diamond band. At higher excitation power of 10 mW we indicate signs of a parityconserving transition at ∼ 2.03 eV supported by saturation measurements. For GeV − we demonstrate that the PLE spectrum is in good agreement with the mirror image of the PL spectrum of the zero-phonon line (ZPL). Experimentally we do not observe a higher lying energy level up to a transition wavelength of 460 nm. The observed PL spectra are identical, independent of excitation wavelength, suggesting a rapid decay to 2 E u excited state and followed by optical transition to 2 E g ground state. Our investigations convey important insights for future quantum optics and quantum sensing experiments based on SiV − -center and GeV − -center in diamond.

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

“…The rest 30–40% of photons comprise phonon‐side band (PSB) that spans tens of nanometers in red end of the spectrum by interacting with phonons . These photons can be spectrally filtered out to serve as a routine probe for photoluminescence excitation (PLE) measurement or population dynamics study under resonant excitation …”

“…spectrum by interacting with phonons. [96] These photons can be spectrally filtered out to serve as a routine probe for photoluminescence excitation (PLE) measurement [97] or population dynamics study under resonant excitation. [98]…”

Formation of GeV, SiV, and NV Color Centers in Single Crystal Diamond Needles Grown by Chemical Vapor Deposition

“…The result of subtraction of these two spectra is shown in the insertion. The fitting of this subtraction demonstrates clearly presence of luminescence line feature with the position of maximum at about 602 nm that corresponds to the ZPL of negatively charged GeV color center . The FWHM of this line about 4.6 nm at room temperature was obtained.…”

Made Easy: CW Laser Light Widely Tunable Across the Visible

“…The results shown in Fig. 5 are part of a recently published study on the level structure of a novel class of vacancy centers in diamond [6]. Their spectroscopic characterization over a broad wavelength range from 460 -650 nm at sufficiently high excitation intensities has been enabled by cw OPO technology.…”

“…Fig. 5 shows a series of photoluminescence excitation spectra of so-called color centers in diamond at room temperature [6]. Color centers are local defects (vacancies) in the diamond lattice related to impurities, and have gained considerable attention over the last decade -not least as potential single photon emitters, which are the heart of many promising quantum technologies such as quantum computing and quantum cryptography.…”