arXiv subjects

A. V. Gritsienko

Publications and source records attributed to A. V. Gritsienko.

3 recordsLinked to original sources

arXiv2026

Near surface donor-acceptor pairs in hydrogenated homoepitaxial diamond nanolayers

Hydrogen-terminated diamond is known for its p-type surface conductivity, which arises from a near-surface hole accumulation layer induced by adsorbed acceptor species. Here, we demonstrate that these surface acceptors also form optically active donor-acceptor pairs (DAP) with substitutional nitrogen donors in diamond. The insertion of a nominally undoped CVD interlayer between a nitrogen-rich HPHT substrate and a hydrogen-terminated surface enables the precise tuning of the donor-acceptor separation with nanometer precision. Radiative DAP recombination appears as bright, spectrally narrow lines whose intensity, energy, and decay dynamics depend systematically on interlayer thickness. Individual lines show single-photon statistics, while ensembles exhibit strong polarization anisotropy reflecting the planar donor-acceptor geometry. These findings reveal an optical counterpart of hydrogen-induced surface transfer doping in diamond and establish a surface-defined, nanometer-tunable platform for engineering DAP-based quantum emitters.

quant-ph↗

arXiv2026

Tuning of SiV quantum emission in nitrogen-doped nanodiamonds by dual-color excitation

The charge dynamics of silicon-vacancy (SiV) centers have been investigated for the first time in high-pressure high-temperature nanodiamonds (NDs) with varying concentrations of substitutional nitrogen (Ns). We demonstrate a controlled sixfold enhancement of SiV- photoluminescence (PL) under dual-color excitation, consisting of strong red (~660 nm) illumination combined with weak green (~530 nm) excitation. The measured dependencies of SiV- PL lifetime and intensity on excitation wavelength, together with the enhancement dependence on Ns concentration in the studied nanodiamonds, provide unambiguous evidence of the involvement of donor nitrogen in SiV-emission dynamics. Saturation curves and second-order PL intensity correlation measurements further indicate suppression of the population of the optically inactive SiV2- state upon the addition of green excitation. These results unlock a practical pathway toward engineering optically-controlled and scalable quantum emitters based on SiV-luminescent diamond nanoparticles.

quant-ph↗

arXiv2025

Single-photon sources created by nature millions of years ago

Single photons source (SPS) is a key component required by quantum communication devices. We report the finding of bright diamond-based SPS created by nature millions of years ago. It is shown that narrow ($\leq$ 2 nm) lines observed within the 500-800 nm range in photoluminescence (PL) spectra of the surface layer of untreated Yakut diamonds rich in nitrogen and hydrogen belong to SPS. Moreover, unknown narrow-line PL observed earlier in nitrogen- and hydrogen-rich diamonds from various deposits around the world are thought to be associated with SPS. Thus, the diamond rim, which until now was sent to the dumps or, at best, used as an abrasive powder, turned out to be a valuable material suitable for use in quantum technologies.

quant-ph↗