We report on the coherence properties of single photons from chromium-based color centers in diamond. We use field-correlation and spectral line-shape measurements to reveal the interplay between slow spectral wandering and fast dephasing mechanisms as a function of temperature. The zero-phonon transition frequency and its linewidth follow a power-law dependence on temperature, which is consistent with direct electron-phonon coupling and phonon-modulated Coulomb coupling to nearby impurities, which are the predominant fast dephasing mechanisms for these centers. Further, the observed reduction in the quantum yield for photon emission as a function of temperature suggests the opening of additional nonradiative channels through thermal activation to higher-energy states and indicates a near-unity quantum efficiency at 4 K.
|Number of pages||6|
|Journal||Physical Review B: Condensed Matter and Materials Physics|
|Publication status||Published - 2012|