Silicon-vacancy center in plasmonic nanoresonators (Conference Presentation)

Abstract

In recent years, silicon-vacancy (SiV–) center has gained significant attention due to its outstanding properties: strong zero-phonon line (ZPL) emission (~70%), robustness to the fabrication process, nearly lifetime limited optical linewidths, and lifetime-comparable spectral diffusions in nano-structures. Metallic nano-resonator can strongly enhance the spontaneous decay rate and pumping intensity, which is suitable for enhancing single photon emission. In this work, we use circular and bow-tie apertures to engineer the emission of SiV– centers. Simulations show that the Purcell enhancements for circular aperture with diameter of 110 nm and for bowtie aperture with 20 nm gap are ~15 and ~90, respectively. We used e-beam lithography followed by reactive ion etching (RIE) to create diamond pillars with embedded SiV– centers. Next, gold was deposited using e-beam evaporation followed by 650°C annealing for 7 minutes. Finally, sonication and lift-off were performed to get clean diamond gold apertures. Preliminary measurements show that SiV– centers inside circular apertures can have lifetime as short as 0.2 ns, which represents a ~9-fold reduction over a ~1.8 ns value typical for SiV– in bulk diamond. Given that the non-radiative relaxation might be large in SiV– center, the actual Purcell enhancement should be larger than 9. Interestingly, SiV– transitions inside apertures span a relatively wide wavelength range (10 nm) compared to that of bulk (< 1 nm), likely caused by large local strain introduced by our fabrication process.