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

A.A. Razgulov, Sergey G. Lyapin, A.P. Novikov +1 more

Stefan Häußler, Gergő Thiering, Andreas Dietrich +8 more

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 to and perform power-dependent saturation measurements. For SiV − our experimental results confirm the presence of a higher energy transition at . By comparison with detailed theoretical simulations of the imaginary dielectric function we interpret the transition as a dipole-allowed transition from -state to -state where the corresponding a 2 u -level lies deeply inside the diamond valence band. Therefore, the transition is broadened by the diamond band. At higher excitation power of we indicate signs of a parity-conserving transition at 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. Experimentally we do not observe a higher lying energy level up to a transition wavelength of . The observed PL spectra are identical, independent of excitation wavelength, suggesting a rapid decay to excited state and followed by optical transition to ground state. Our investigations convey important insights for future quantum optics and quantum sensing experiments based on SiV − -center and GeV − -center in diamond.

Maxime Bergamin

Amanuel M. Berhane, Sumin Choi, Hiromitsu Kato +4 more

Electrically driven emission from negatively charged silicon-vacancy (SiV)− centers in single crystal diamond is demonstrated. The SiV centers were generated using ion implantation into an i region of a p-i-n single crystal diamond diode. Both electroluminescence and the photoluminescence signals exhibit the typical emission that is attributed to the (SiV)− centers. Under forward and reversed biased PL measurements, no signal from the neutral (SiV)0 defect could be observed. The realization of electrically driven (SiV)− emission is promising for scalable nanophotonics devices employing color centers in single crystal diamond.

Neli Laštovičková Streshkova

In this work, we focus on the interaction of SiV color centers in diamond with femtose- cond light pulses. In the theoretical part, a script is developed to simulate the experimen- tal varying stripe length method and the effects of saturated optical gain are investigated. In the experimental part, photoluminescence and transient differential absorption under non-resonant excitation are studied. The result of the luminescence measurements are estimates of the effective cross-sections of single-photon absorption for the wavelengths 620 nm, 515 nm and 340 nm, as well as the effective cross-section of three-photon absorp- tion for 2000 nm. The result of the differential absorption measurements is the relaxation constant of the excited level of the SiV center and the upper estimate of the time duration of the initial dynamics. 1

Zuanquan Chen, Sen Zhang, Benjian Liu +9 more