Southwest Quantum Information and Technology

Cavity QED of silicon vacancy centers with a silica optical microresonator

Presenting Author: Abigail Pauls, University of Oregon
Contributing Author(s): Ignas Lekavicius, Hailin Wang

Negatively charged silicon-vacancy (SiV) centers in diamond feature an inversion symmetry, making the SiV optical transitions robust against charge fluctuations in the surrounding environment. SiV centers have been successfully integrated into photonic crystals for cavity QED studies and for the development of optical quantum networks. Diamond photonic crystals, however, feature a relatively broad optical linewidth (~ 50 GHz), limiting this platform to the bad cavity limit in cavity QED. We report the development of an experimental platform combining a thin diamond membrane with a thickness of about 110 nm and a tunable silica optical microresonator with a diameter near 50 micrometers. This composite system can feature an optical cavity linewidth as narrow as 40 MHz, enabling the achievement of the good cavity limit in cavity QED. The diamond membranes were fabricated with reactive ion etching from a bulk film of electronic grade diamond. Photoluminescence excitation spectra of SiV centers at 10 K show linewidths ranging from 200 to 300 MHz for membranes as thin as 100 nm. For cavity QED studies, a 110 nm thick diamond membrane is in contact with a silica microsphere. Whispering gallery mode (WGM) linewidths near 40 MHz have been observed for the composite membrane-microsphere system. This composite cavity QED system provides a highly promising platform for pursuing cavity QED of SiV centers in the good cavity limit. This work is supported by NSF.

(Session : from 5:00pm - 7:00pm)