Metal-dielectric antennas for efficient photon collection from diamond color centers

Abstract

A central challenge in quantum technologies based on atom-like defects is the efficient collection of the emitter's fluorescence. Optical antennas are appealing as they offer directional emission together with spontaneous emission rate enhancement across a broad emitter spectrum. In this work, we introduce and optimize metal-dielectric nanoantenna designs recessed into a diamond substrate and aligned with quantum emitters. We analyze tradeoffs between external quantum efficiency, collection efficiency, radiative Purcell factor, and overall collected photon rate. This analysis shows that an optimized metal-dielectric hybrid structure can increase the collected photon rate from a nitrogen vacancy center by over two orders of magnitude compared to a bare emitter.

Spin Readout Techniques of the Nitrogen-Vacancy Center in Diamond

“…The current solution to this problem is to work at very high magnetic fields where hyperfine-induced bit-flip errors are reduced, but radiative lifetime engineering that reduces the excited-state lifetime presents an alternative approach. Achievable radiative rate enhancements of up to two orders of magnitude [ 91 , 92 , 139 ] could increase the nuclear-spin by a similar factor, enabling higher-fidelity measurements or relaxing the field constraints. Alternatively, combinations of nuclear-assisted and SCC readout protocols could take advantage of SCC’s wide measurement tunability to limit the total number of optical cycles while maintaining overall SNR.…”

“…Figure 3 a–c shows three recent examples of plasmonic devices designed to engineer the emission dynamics of NV centers in nanodiamonds or close to the surface of bulk diamond. Several recent studies have further considered metal-dielectric hybrid systems that optimize both directionality and radiative lifetime reduction [ 89 , 90 , 91 ]. Computational results predict that a hybrid bow-tie structure like the one shown in Figure 3 c can produce a strong Purcell enhancement together with highly directional emission ( Figure 3 d), providing an attractive alternative to all-dielectric diffractive designs.…”

“…“MD” stands for metal-dielectric. See [ 91 ] for details on the design variations in (d). Panel (a) is reprinted with permission from [ 76 ].…”

Hyperbolic metamaterial resonator–antenna scheme for large, broadband emission enhancement and single-photon collection

“…The peak CPR value of about 80 at 900 nm corresponding to the emission of silicon-carbide quantum emitters. This is therefore a stateof-the art improvement considering that the previous computational design using a hybrid 15 bowtie metal-dielectric antenna has reported a maximum average CPR of 25 across the NV emission spectrum of 600 nm to 800 nm with the highest value being about 40 at 650 nm [27]. In this calculation, the NV dipole is considered to be located at the centre of the bowtie with its orientation along the bowtie axis.…”

Hyperbolic Metamaterial with Quantum Dots for Enhanced Emission and Collection Efficiencies

“…The performance of the HMM/Ag antenna structure is then computationally evaluated in terms of the Purcell factor and collection efficiency (CE). The CE is defined from the spatial overlap of the total radiated power and the numerical aperture (NA) of the collection objective [35] as the ratio of the total power incident on the objective lens to the total power radiated by the emitter. The effectiveness of any out-coupling scheme is quantified in terms of both F P and CE.…”