Purcell and Collection Efficiency Enhancement of Single NV‐ Center Emission Coupled to an Asymmetric Tamm Structure. Issue 4 (7th February 2023) - Singh, Nitesh
Abstract: The resonant modes associated with engineered photonic structures of different spatial‐dimension are essential to obtain bright on‐demand single photon sources for quantum technologies. Negatively‐charged nitrogen‐vacancy (NV‐) center in diamond is proposed as an excellent single‐photon source at room temperature. The possible optical readout of spin states in diamond makes it a good candidate for the spin‐photon interface. However, poor light collection, feeble zero‐phonon line, low emission rate, and broad phonon‐induced emission limit the use of NV‐ centers in quantum technologies. Here, a feasible, easy‐to‐fabricate, asymmetric Tamm structure coupled with a single NV‐ center to enhance the emission rate of zero phonon line (ZPL) with better light collection efficiency is presented. The asymmetric Tamm structure shows dual resonant mode with one of the modes coinciding with NV‐ ZPL wavelength of 640 nm. The mode quality factor ( Q ‐factor) is 140, which is greater than the Q ‐factor of conventional Tamm structure and hence, improved field intensity localization. The authors achieved four times Purcell enhancement and five times enhanced light collection efficiency at 640 nm. The proposed asymmetric Tamm structure helps to generate bright single photons using NV‐ center and improves the efficacy of the spin‐photon interface. Abstract : An asymmetric Tamm cavity coupled to a nitrogen‐vacancy (NV) center shows improved emission enhancement and far‐field collection at the zero phonon line wavelength 640 nm. The asymmetric Tamm cavity structures exhibit better quality factors and thus improving the cavity‐NV center coupling. The coupling provides four‐times emission and five‐times light collection enhancements paving the way for bright single photon emission.