Engineering the spontaneous emission of diamond color centers using photonic structures

Petr Siyushev

Mikhail Y. Shalaginov

Light-matter interaction is the foundation for numerous important quantum optical phenomena, which may be harnessed to build practical devices with higher efficiency and unprecedented functionality. Nanoscale engineering is seen as a fruitful avenue to significantly strengthen light-matter interaction and also make quantum optical systems ultra-compact, scalable, and energy efficient. This research focuses on color centers in diamond that share quantum properties with single atoms. These systems promise a path for the realization of practical quantum devices such as nanoscale sensors, single-photon sources, and quantum memories. In particular, we explored an intriguing methodology of utilizing nanophotonic structures, such as hyperbolic metamaterials, nanoantennae, and plasmonic waveguides, to improve the color centers performance. We observed enhancement in the color center’s spontaneous emission rate, emission directionality, and cooperativity over a broad optical frequency range. Additionally, we studied the effect of plasmonic environments on the spin-readout sensitivity of color centers. The use of CMOS-compatible epitaxially grown plasmonic materials in the design of these nanophotonic structures promises a new level of performance for a variety of integrated room-temperature quantum devices based on diamond color centers.

Sachin Kumar Sharma, Ashish, Rajesh V. Nair

The defect centers in solid-state materials especially the nitrogen-vacancy (NV) centers in diamond have shown a tremendous potential for their utilization in quantum technology applications. However, they exhibit certain drawbacks such as the feeble zero phonon line with huge phonon contribution and the higher lifetime values. Here, we present a novel approach to control the spontaneous emission from NV centers in nanodiamond using engineered self-assembled photonic crystals. Using two complimentary emission measuring geometries at room temperature, we show a 63% suppression and 17% enhancement of NV center emission intensity using photonic stopgap, supported with simulations. The emission rates are modified in a broad spectral range of NV center emission and are consistent with the Barnett–Loudon sum rule. The results are crucial for emerging quantum technologies using NV centers in diamond.

F. C. Waldermann, P. Olivero, Joshua Nunn +10 more

Shahriar Aghaeimeibodi, Alison E. Rugar, Daniel Riedel +8 more

Building quantum networks requires efficient coupling of solid-state quantum emitters to photonic devices. Tinvacancy center (SnV) has attracted much interest for having long spin coherence times at temperatures above 1 K. Employing SnV as an optically addressable qubit requires integration with photonic structures to both route the emitted photons and enhance the light-matter interaction. We present incorporation of high-quality SnV centers with narrow linewidths in suspended diamond waveguides. Furthermore, we fabricate photonic crystal cavities in diamond with embedded SnV centers. We observe strong intensity enhancement of the photon emission when the cavity is resonant with the color center. Time-resolved photoluminescence measurements confirm that this effect is due to radiative Purcell enhancement of the spontaneous emission. Finally, we demonstrate Stark tuning of transition frequency of SnV centers, essential for multiemitter applications. These results are a significant step toward color-center-based quantum information processing applications without the need for dilution refrigerators.

Michelle Chalupnik, Erik Knall, Bartholomeus Machielse +3 more