Introduction
Researchers from IonQ (via Lightsynq Technologies), Element Six (a De Beers Group company), and Amazon Web Services achieved a significant breakthrough in the development of quantum-grade diamond thin films. The ability to produce high-quality, high-yield diamond thin films opens the door to manufacturing diamond devices at industrial scale – a capability directly relevant for technologies such as IonQ’s memory-enhanced photonic interconnects and repeaters. Ultimately, this advancement enables development of higher-performing interconnects by leveraging established semiconductor fabrication techniques and infrastructure, and is overall an inflection point in diamond’s capabilities as a semiconductor material.
Diamond thin films and the capabilities they enable build upon over 70 years of pioneering work conducted by Element Six. Part of the De Beers Group, Element Six has harnessed the extreme properties of synthetic diamond to open up new possibilities in areas such as photonics, acoustics, power transmission, water treatment, thermal management and sensors. The company’s advanced material solutions are used in a wide range of applications across multiple industries including manufacturing in the automotive and consumer electronics industries, cutting and drilling in the oil and gas industry, and in components for mining, road, construction and agriculture applications.
The Path to Scalable Quantum Computing
IonQ has always believed that building quantum computers from modular, interconnected quantum processing units (QPUs) is the most effective path to datacenter-scale systems. This modular approach has proven incredibly successful in classical computing (see e.g. NVIDIA’s acquisition of InfiniBand technology via Mellanox) and we believe holds a similar promise for quantum technologies.
Of particular importance to modular architectures is the ability to leverage high-quality, high-yield manufacturing techniques refined by the semiconductor industry over the past few decades. IonQ's acquisition of Oxford Ionics is a prime example of the value derived from applying standard semiconductor fabrication techniques to achieve scale via replication rather than reinvention.
The other vital component for realizing datacenter scale quantum computers is the network fabric itself. IonQ, via Lightsynq (acquired in June 2025), currently develops leading quantum interconnect systems that will form the backbone for scalable quantum architectures. These interconnects will also unlock new applications in quantum communications, networked quantum sensing, and more. IonQ’s latest interconnect technology relies on quantum memories made from quantum-grade synthetic diamond – a semiconductor material that has historically been limited to specialized, small-scale academic fabrication methods.
This reliance on small-scale, custom fabrication might appear to be an obstacle towards industrial-scale, standardized processing. However, thanks to the recent development of quantum-grade diamond thin films by a team of researchers from IonQ, Element Six, and Amazon Web Services, this is an obstacle no more.
From Lab to Fab: The Power of Quantum-Grade Diamond Thin Films
In essence, the research team developed a technique to create thin films of diamond and bond them onto other semiconductor substrates, such as silicon. Importantly, these diamond films meet the stringent requirements for use in advanced quantum devices like memories. Quantum-grade diamond films offer many advantages, with two particularly significant benefits being foundry compatibility and heterogeneous integration.
Foundry Compatibility: The combination of diamond thin films with highly mature semiconductor substrates like silicon or silicon nitride allows for the implementation of standard, foundry-compatible fabrication processes – methods previously not viable for diamond. Ultimately, integration into professional foundries will enable manufacturing of diamond quantum devices beyond small-scale R&D cleanrooms. This transition leverages the over $1T of investment in the semiconductor industry, addressing a major scaling challenge for various technologies. These include quantum memories (like silicon vacancy memories), diamond-based quantum sensors (like nitrogen vacancy sensors), and microelectromechanical systems (MEMS), which have applications in areas like inertial navigation.
Steps of the thin film production process. Top: Schematic representation of the processing step. Bottom: Real-world imagery of the corresponding steps.
Heterogeneous Integration: Heterogeneous integration refers to the process of combining multiple individual components – often made from different materials or using different manufacturing processes – into a single system-level package. This overcomes limitations of single material approaches and empowers designers to select the best possible components for each function, regardless of the material platform used. Our diamond thin films can be heterogeneously integrated with a variety of substrates, which allows us to merge the cutting-edge quantum performance of diamond with the mature, proven materials and components from the classical semiconductor industry. For instance, IonQ’s diamond chip-based quantum memories can now be integrated with functionalized substrates featuring electronic control lines which can be used for more efficient control of quantum memories. In the future, the thin-film platform will enable integration of quantum memories into complex photonic integrated circuits, featuring components like switches, modulators, and detectors, made from mature materials like silicon nitride.
Left: A 3x3 grid of diamond films (small translucent squares with spacing of 5 mm) bonded onto a silicon carrier (large black square). Right: A zoomed-in image of a diamond film. The film measures approximately 0.5 x 0.5 mm^2. Other semiconductor materials can be heterogeneously integrated alongside diamond, dramatically increasing the suite of capabilities available for a system-level package.
Conclusion
Our ability to produce high-quality, high-yield, and foundry-compatible diamond thin films represents a pivotal moment in diamond’s evolution as an industrially useful semiconductor material. In the quantum sector, this breakthrough means that both the computing and networking hardware at the heart of IonQ's quantum systems can leverage foundry-scale semiconductor processing to accelerate progress. This capability applies to IonQ’s acquisition of Oxford Ionics for computing, and to IonQ’s diamond quantum memory platform for networking at datacenter-scale and beyond. The same benefits extend beyond quantum computing and networking, offering new possibilities for other advanced technologies, such as NV-diamond quantum sensors to enable improved GPS-denied navigation.The importance of these and other quantum sensing applications is highlighted by IonQ's recently announced acquisition of Vector Atomic, establishing IonQ as the most complete quantum platform, delivering a full suite of solutions across compute, networking, and sensing applications.
Interested readers can find the paper preprint on arXiv.