Material innovations underpin many of the exciting applications offered by emerging quantum technologies, writes Dr Tess Skyrme, senior technology analyst at IDTechEx.
IDTechEx’s latest report, “Quantum Technology Market 2024-2034: Trends, Players, Forecasts”, compares platforms based on superconductors, silicon photonics, alkali vapors, semiconductors, nanomaterials, and more. Each is seeking to enable solutions for quantum computing, sensing and communications with various advantages and disadvantages for each method.
However, of them all, the lab-grown diamond has arguably the greatest potential to overcome one of the quantum technology markets’ biggest problems: cooling.
Nitrogen-vacancy (NV) centres, or colour centres, are found naturally within diamond. These colour centres have an associated spin-state, which, when illuminated with green light, will emit red light. The intensity of this fluorescence depends on the spin state, and simple imaging techniques can, therefore, be used for the “read-out” of diamond-based quantum computing processor chips or quantum sensors.
Diamond is unique in that protection of the quantum properties from external noise does not require a cooling system. Many material platforms require complex refrigeration or laser cooling to reduce noise, increasing costs, device footprints, and power consumption. This is not only an issue for superconductors, but even silicon-spin or photonic designs often have a sub-zero temperature requirement somewhere within the system.
However, the carbon lattice structures of diamond create a natural insulation from noise, which is effective at room temperature.
However, although colour centres can occur naturally in diamonds, they are typically too random and sparse for practical use within quantum technologies. Instead, techniques developed to produce lab-grown diamonds are being adapted so that N-V centers can be implanted and manufactured to the specifications quantum OEMs require.
There is increased start-up activity resulting from the potential simplicity of diamond-based quantum technologies.
Within quantum computing, Australia’s Quantum Brilliance closed a $18-million funding round in 2023 – with a mission to bring the technology from the “lab to the data centre”. The company cites the advantage of small form-factor, robust design, and low power consumption as key attributes of their diamond-based platform.
Indeed, small, desktop-sized diamond-based “quantum computers” have already been sold into education as a teaching instrument in China.
Yet, compared to other quantum computing approaches, diamond is still lagging. IBM’s superconducting approach recently broke through the 1 000 qubit barrier, while diamond systems mostly offer access to just one, or a “handful”.
Although quantum computing typically gets more attention, the opportunities in quantum sensing shouldn’t be overlooked. This is particularly true of the diamond platform, where overcoming challenges with size, weight, and power is a ubiquitous challenge for the quantum sensor market.
In the last 10 years, players such as QZabre and Qnami have commercialised microscope tips using N-V centers in diamond, while SBQuantum have focused on magnetomers for imaging or navigation.
Historically, the technology has predominantly been developed by Lockheed Martin and others for aerospace and defense, but looking ahead it could go more mainstream within autonomous vehicles and consumer electronics. This has motivated players such as Bosch to incubate its own start-up dedicated to this opportunity.
Becoming more established
While many of the start-ups and spin-outs active today are finding novel ways to use N-V centers, others have been more instrumental in refining the manufacturing process. Element Six of the De Beers Group is the most dominant force here, with a long history of investment in advancing the chemical vapor deposition (CVD) methods required. Indeed, next-generation technologies are now a key strategy for the historic jewelry supplier, but competition is mounting.
Specialist, small-scale foundries can be found in laboratories worldwide with specific expertise in refining the manufacturing for specific quantum applications. German-based Diatope, founded in 2021, aims to go one step further and offer not only reliable, reproducible, and stable supply but also offer thorough quality control checks prior to dispatch using laser microscopy. Similarly, consortiums of players within the lab-grown diamond ecosystem, such as LGD in Tech, are forming to help build connections in emerging technology sectors such as quantum.
Reality hits and the long-term future
The scalability challenges hinted at in relation to diamond for quantum computing are ultimately a significant barrier to adoption within the industry to date. Chip sizes are typically limited to a few mm square, and even these can cost upwards of $5 000. Diamond is also inherently harder to process and much harder to etch than silicon.
Moreover, diamond is not the only nanomaterial seeking to shake up the quantum technology market. 2D materials such as carbon nanotubes and metal-organic frameworks (MOFs) are also being investigated for quantum computing. Novel wide-bandgap semiconductors may also encroach on some of the diamond’s territory in the long term.
Despite some of the many challenges, the room-temperature operability of lab-grown diamond-based quantum technology remains a very compelling opportunity for investors, start-ups, and established companies alike. Whether it be more scalable quantum computer architectures or tinier high-performance sensors, this novel material is likely to be found in far more locations than ethical jewelry stores in the next decade.