title: Investigation of Line Width Narrowing and Spectral Jumps of Single Stable Defect Centers in ZnO at Cryogenic Temperature.
abstract: Finding new solid state defect centers in novel host materials is crucial for realizing integrated hybrid quantum photonic devices. We present a preparation method for defect centers with photostable bright single photon emission in zinc oxide, a material with promising properties in terms of processability, availability, and applications. A detailed optical study reveals a complex dynamic of intensity fluctuations at room temperature. Measurements at cryogenic temperatures show very sharp (<60 GHz) zero phonon lines (ZPLs) at 580 nm to  620 nm (≈ 2.0 eV) with frozen out fast fluctuations. Remaining discrete jumps of the ZPL, which depend on the excitation power, are observed. The low temperature results will narrow down speculations on the origin of visible-near-infrared (NIR) wavelength defect emission in zinc oxide and provide a basis for improved theoretical models.
authors: †Humboldt-Universität zu Berlin, Institut für Physik, Newstonstraße 15, 12489 Berlin, Germany.
authors: Oliver
authors: O
authors: Neitzke
authors: ‡Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany.
authors: Anthony
authors: A
authors: Morfa
authors: †Humboldt-Universität zu Berlin, Institut für Physik, Newstonstraße 15, 12489 Berlin, Germany.
authors: Janik
authors: J
authors: Wolters
authors: †Humboldt-Universität zu Berlin, Institut für Physik, Newstonstraße 15, 12489 Berlin, Germany.
authors: Andreas W
authors: AW
authors: Schell
authors: †Humboldt-Universität zu Berlin, Institut für Physik, Newstonstraße 15, 12489 Berlin, Germany.
authors: Günter
authors: G
authors: Kewes
authors: †Humboldt-Universität zu Berlin, Institut für Physik, Newstonstraße 15, 12489 Berlin, Germany.
authors: Oliver
authors: O
authors: Benson
keywords: ZnO nanomaterial; cryogenic temperature study; narrow-band emitter; quantum optics; single photon source