Isotopically varying spectral features of silicon-vacancy in diamond

Abstract

The silicon-vacancy centre ( ${\rm Si}{{{\rm V}}^{-}}$ ) in diamond has exceptional spectral properties for single-emitter quantum information applications. Most of the fluorescence is concentrated in a strong zero phonon line (ZPL), with a weak phonon sideband extending for 100 nm that contains several clear features. We demonstrate that the ZPL position can be used to reliably identify the silicon isotope present in a single ${\rm Si}{{{\rm V}}^{-}}$ centre. This is of interest for quantum information applications since only the ^29 Si isotope has nuclear spin. In addition, we show that the sharp 64 meV phonon peak is due to a local vibrational mode of the silicon atom. The presence of a local mode suggests a plausible origin of the measured isotopic shift of the ZPL.

Keywords

• silicon vacancy center
• diamond
• isotope
• local vibrational mode
• phonon sideband
• ZPL