In a groundbreaking advancement poised to revolutionize quantum technology, researchers from the Hebrew University of Jerusalem, in collaboration with Humboldt University in Berlin, have developed an innovative method to capture nearly all emitted photons from nitrogen-vacancy (NV) centers embedded within nanodiamonds. This breakthrough addresses one of the long-standing challenges in the field of quantum optics: efficient photon collection at ambient conditions. Unlike conventional approaches where emitted photons scatter in multiple directions, this innovative system funnels light in a controlled manner, achieving an unprecedented collection efficiency of up to 80% at room temperature.
Nitrogen-vacancy centers are atomic-scale defects within a diamond lattice that function as highly stable and easily controllable quantum emitters. These centers have been the focus of intense research due to their unique properties, including the ability to emit single photons on demand. Single photon sources are fundamental to developing quantum communication networks, ultra-sensitive magnetometers, and qubits for quantum computing. However, conventional nanodiamonds with NV centers suffer from inefficient photon extraction as the emitted photons disperse isotropically, making collection a significant technical bottleneck.
Addressing this limitation, the research team engineered a hybrid nanoantenna structure that integrates layers of metallic and dielectric materials arranged in a bullseye pattern surrounding the nanodiamond. This nanoantenna acts like an architectural lighthouse, directing the emitted photons into a concentrated beam rather than allowing them to scatter randomly. The bullseye design utilizes concentric rings that enhance the constructive interference of emitted light, effectively funneling photons into a narrower emission profile.
Crucially, the researchers employed an ultra-precise fabrication technique that enables the placement of individual nanodiamonds at the exact center of the bullseye nanoantenna with nanometer precision. This meticulous positioning is essential because even slight misalignments could severely degrade the antenna’s ability to direct photons efficiently. By ensuring the nanodiamond’s NV center sits precisely at the electromagnetic hotspot of the antenna, the team maximized the coupling between the quantum emitter and the photonic structure.
The device operates effectively at room temperature, a pivotal advantage over many quantum photonic systems that require cryogenic cooling to maintain performance. This characteristic opens the door to real-world applications where practical integration with existing technologies is essential. By bridging the gap between laboratory prototypes and commercially viable devices, this research marks a major milestone toward scalable quantum communication and sensing systems.
The technological implications of this development extend beyond just efficient photon collection. Enhanced directionality of light emission can lead to significant improvements in the optical signal-to-noise ratio, allowing quantum information to be transmitted with higher fidelity and over longer distances. Such capabilities are essential for building quantum-secured communication channels that are immune to eavesdropping and for creating high-precision quantum sensors capable of detecting minuscule magnetic or electric fields.
Experimental validation of this approach demonstrated that up to 80% of photons emitted from NV centers in the hybrid nanoantennas could be collected using standard optics at room temperature. This figure surpasses previous benchmarks where less than a third of emitted photons were typically collected under similar conditions. The difference carries monumental importance for practical quantum devices since photon loss directly translates to reduced efficiency and increased error rates.
Beyond the immediate application in quantum photonics, the research exemplifies the power of interdisciplinary collaboration involving material science, nanofabrication, quantum physics, and optical engineering. By carefully optimizing the interaction between light and matter on the nanoscale, the team showcased how subtle structural engineering can drastically enhance quantum device performance. It is a vivid demonstration of how merging classical photonic design principles with quantum emitters produces devices that harness the quantum realm more effectively.
Prof. Rapaport, a lead researcher on the project, emphasized the transformative potential of the new platform: “Our system brings us tantalizingly close to the theoretical limits of photon collection efficiency. With this kind of precision and design, quantum devices that were once purely experimental can now become practical tools driving new technologies in secure communications and sensing.” His statement underlines the transition from proof-of-concept experiments to scalable quantum technology platforms.
Moreover, Dr. Boaz Lubotzky highlighted the user-friendly nature of the design, noting its compatibility with chip-based fabrication methods and operation at room temperature. This ease of integration facilitates incorporation into existing photonic circuits and modular quantum systems without the burdensome need for complex cooling infrastructure. The chip-scale approach is critical for future quantum networks requiring compact, reliable components.
This pioneering work not only deepens our understanding of light-matter interactions within nanophotonic devices but also positions nanodiamond-based quantum emitters as front-runners in the race toward next-generation quantum technologies. While diamonds have been treasured for their aesthetic beauty for centuries, their emerging role as a foundation for secure quantum communication and highly sensitive detection devices exemplifies the unexpected utility of natural materials in cutting-edge tech.
Looking ahead, the team’s success affirms that overcoming physical constraints at the nanoscale can unlock dramatic enhancements in quantum device performance. As quantum computing and communication technologies edge closer to commercialization, improvements such as these are crucial for maintaining coherence, increasing data transmission rates, and achieving practical deployment in everyday technologies. The methodology demonstrated here provides a versatile platform that can be adapted and expanded to other types of quantum emitters and photonic architectures.
In summary, the innovative coupling of nanodiamonds containing nitrogen-vacancy centers with an ultra-precisely positioned hybrid bullseye nanoantenna heralds a new era of efficient, practical quantum photonics. Achieving near-unity photon collection at room temperature is not just a technical triumph but a critical step enabling secure quantum networks, advanced quantum sensors, and ultimately, scalable quantum information processing. The research published in APL Quantum stands as a pivotal contribution, bridging the gap between fundamental quantum emitter physics and real-world quantum technology applications.
Article Title: Approaching unity photon collection from NV centers via ultra-precise positioning of nanodiamonds in hybrid nanoantennas
News Publication Date: 17-Sep-2025
Web References: http://dx.doi.org/10.1063/5.0272913
Image Credits: Boaz Lubotzky
Keywords: Quantum computing, Computational science, Quantum optics, Nanotechnology
