Natural Diamond Rims Exhibit Bright Single Photon Emission for Quantum Technologies

Single photons are fundamental to emerging technologies such as quantum computing and secure communication, and creating efficient sources of these particles remains a significant challenge. Now, researchers led by D. G. Pasternak and A. M. Romshin at the Prokhorov General Physics Institute, along with colleagues including R. A. Khmelnitsky from the Lebedev Physical Institute, report the discovery of naturally occurring, bright single-photon sources within diamonds. The team demonstrates that narrow bands of light emitted from the surface of Yakut diamonds, rich in nitrogen and hydrogen, originate from these unique sources, and that similar emissions observed in diamonds from around the world likely share the same origin. This finding transforms what was previously considered waste material, the outer layer of diamonds often discarded or used as an abrasive, into a potentially valuable resource for advanced technological applications.

Single photon sources (SPS) represent a key component required by quantum communication devices. This work reports the finding of bright, diamond-based SPS created naturally millions of years ago. The research demonstrates that narrow (≤ 2 nm) lines observed within the 500-800 nm range in photoluminescence spectra of the surface layer of untreated Yakut diamonds, rich in nitrogen and hydrogen, belong to these sources. Previously observed, unknown narrow-line photoluminescence in nitrogen- and hydrogen-rich diamonds is now identified as originating from these single photon emitters.

Hydrogen Termination Creates Stable Photon Emission

This research details the investigation of narrow-band luminescence observed in hydrogen-terminated nanodiamonds, potentially offering a source of stable single photons at room temperature. The study focuses on understanding how hydrogen termination of nanodiamond surfaces creates specific defect states that contribute to the observed luminescence. These defects act as donor-acceptor pairs, facilitating recombination emission and offering promise for quantum technologies. Researchers observed stable, narrow-band luminescence in these nanodiamonds, distinct from the broader emission typically seen in diamond. This emission is remarkably stable and operates at room temperature, a significant advantage for practical applications, and offers potential advantages compared to other single-photon source materials like silicon carbide and hexagonal boron nitride. The research opens up possibilities for developing robust and efficient single-photon sources for quantum communication, quantum computing, and quantum sensing, and could also be utilized in advanced biomedical imaging techniques.

Nitrogen-Hydrogen Defects Emit Bright Single Photons

Researchers have discovered a source of bright, single photons originating from the surfaces of natural diamonds, a finding that could significantly advance technologies reliant on precise light emission. These diamonds, commonly found and previously discarded as low-quality material, contain narrow bands of light emission within their surface layers, revealing an unexpected abundance of single photon sources. Detailed analysis reveals that these diamonds emit photons with remarkably specific characteristics, exhibiting “sub-Poissonian” statistics, a key indicator that each emission event involves a single photon, crucial for applications like quantum cryptography and quantum computing. The team believes the source of these photons lies in the interaction between nitrogen impurities and hydrogen atoms present on the diamond surface, forming donor-acceptor pairs that recombine to emit light. The energy of the emitted photons is influenced by the vibrations of hydrogen-carbon bonds on the surface, creating a predictable pattern in the emitted spectrum, and allowing for potential tuning of the emitted wavelengths. This discovery offers a potentially abundant and cost-effective source of single photons, moving beyond the reliance on complex and expensive laboratory-grown materials, and highlights the importance of re-evaluating seemingly unusable materials.

Yakutian Diamonds Host Superior Single Photons

This research identifies naturally occurring single photon sources within the surface layers of diamonds sourced from Yakutia, Russia. The team demonstrates that narrow-line emissions observed in the photoluminescence spectra of these nitrogen- and hydrogen-rich diamonds correspond to these sources, exhibiting superior characteristics, narrower emission lines and higher photon emission rates at room temperature, when compared to previously created synthetic sources. This discovery transforms what was previously considered waste material, the diamond rim produced during mining, into a valuable resource for emerging technologies, and suggests that similar single photon sources may exist in nitrogen- and hydrogen-rich diamonds from other locations worldwide. These sources are believed to originate from donor-acceptor pairs associated with nitrogen and hydrogen on the diamond surface, offering a potentially scalable platform for quantum sensing and communication applications.