The uk quantum adjacent companies build the technology that makes quantum computing possible without building the quantum computers themselves, from the cryogenics that cool the chips to the lasers, photonic components, sensors and security hardware around them. Britain is unusually strong in this enabling layer, with world-leading suppliers like Oxford Instruments and a deep bench of quantum-sensing and quantum-security startups. This guide profiles the UK quantum adjacent companies that power the wider quantum supply chain, and explains how they connect to the processor makers in our main computing guide.
1. The supply chain matters as much as the computers. Quantum machines cannot run without cryogenics, lasers, photonic chips and control electronics, and Britain leads in several of these enabling categories.
2. Oxford Instruments is the backbone. Its dilution refrigerators and fabrication tools sit in quantum laboratories worldwide, making it the most established of the enabling suppliers.
3. Quantum sensing is a British strength. Firms like Cerca Magnetics, QLM, Delta g and Aquark turn quantum physics into products for medicine, energy and infrastructure today, not in some distant future.
4. Quantum security is commercialising fast. Arqit, KETS and Quantum Dice deliver quantum-safe encryption, key distribution and random numbers that defend against the coming quantum threat.
5. Lasers and foundries are the hidden enablers. Novacene’s lasers and Kelvin Nanotechnology’s foundry let other companies build and operate quantum hardware at all.
6. Adjacent firms reach revenue sooner. Many of these enabling firms sell working products now, giving Britain commercial quantum income while the computing race continues.
What counts as a quantum-adjacent company?
A quantum-adjacent company makes technology that the quantum sector depends on without itself selling a quantum computer, covering the supply chain, the enabling components and the parallel fields of quantum sensing and quantum communication. The distinction matters because the headlines focus on processor makers, yet no quantum computer works without cryogenics, lasers, photonic chips and control electronics around it. Britain happens to be strongest in exactly this enabling layer.
The category also includes quantum technologies that are not computing at all, such as quantum sensors that measure gravity or brain activity and quantum-safe security products. These use the same underlying physics and talent pool as quantum computing, which is why they cluster around the same universities and regions. Grouping them shows the full breadth of British quantum technology that a computing-only list would miss.
Cryogenics, lasers and the quantum supply chain
The most critical enabling technologies are the ones that let qubits exist and stay stable, above all the cryogenic systems that cool superconducting and spin chips to a fraction of a degree above absolute zero. Oxford Instruments dominates this market globally, and its presence gives Britain a structural advantage that no amount of startup funding could quickly replicate. Fabrication foundries such as Kelvin Nanotechnology then turn device designs into real chips.
Lasers and photonic components form the second pillar of the supply chain, since cold-atom and photonic machines depend on precise light sources and optical parts. Novacene’s lasers and Wave Photonics’ integrated-photonics designs supply that need from within the United Kingdom. This combination of cryogenics, fabrication and photonics makes Britain’s quantum supply chain a strategic asset. The national programme that backs the UK quantum adjacent companies funds this enabling layer alongside the processor makers.
The top UK quantum adjacent companies
Eleven companies illustrate the breadth of the UK quantum adjacent companies, spanning cryogenics and fabrication (Oxford Instruments and Kelvin Nanotechnology), lasers and photonics (Novacene and Wave Photonics), quantum sensing (QLM, Cerca Magnetics, Delta g and Aquark) and quantum security (Arqit, KETS and Quantum Dice). For the processor makers themselves, see our UK quantum computing companies guide, and for the global view our worldwide quantum computing companies guide.
What the lineup shows
The enabling lineup is broader and often more commercially mature than the computing one, because many of these firms sell working products into existing markets. Cryogenics, lasers and sensors all have customers today, which gives Britain real quantum revenue while the processor race plays out. The spread also mirrors the country’s research strengths in photonics, atomic physics and instrumentation.
Quantum sensing and timing
Quantum sensing is where British enabling technology is closest to everyday impact, because the sensors exploit quantum effects to measure magnetic fields, gravity and time with extraordinary precision. Cerca Magnetics builds wearable brain scanners, QLM images greenhouse-gas leaks, Delta g maps the ground beneath our feet, and Aquark shrinks the cold-atom hardware that many sensors need. These are products with paying customers in healthcare, energy and construction.
The sensing field benefits from the same national programme and university base that supports computing, and it often reaches market faster because it does not need full error correction. That makes it a commercial proving ground for the wider sector. Several of these firms are already exporting, which strengthens the case for Britain’s broad quantum strategy.
Quantum security, QKD and random numbers
The other fast-commercialising area is quantum security, which divides into quantum key distribution, quantum random number generation and quantum-safe software. KETS builds key distribution and random numbers onto photonic chips, Quantum Dice produces self-certifying randomness, and Arqit delivers quantum-safe encryption as a service. Together they address the harvest-now-decrypt-later risk that the quantum threat creates.
These firms sit at the boundary between quantum hardware and cybersecurity, and their products complement the migration to post-quantum cryptography rather than competing with it. Our guide to the top post-quantum cryptography companies and our CRQC threat tracker set out why this work matters. Security is one of the most investable corners of British quantum.
How adjacent tech connects to the computing pillar
The enabling companies and the processor makers form one ecosystem rather than two, because the computing firms are customers of the adjacent ones. A superconducting machine from a British or American maker may run inside an Oxford Instruments refrigerator, use Novacene lasers and rely on chips fabricated at Kelvin Nanotechnology. That dependency gives Britain leverage across the whole industry, not just the part that builds processors.
It also means the health of the supply chain shapes the health of computing, since a bottleneck in cryogenics or lasers slows everyone. Tracking the UK quantum adjacent companies alongside the processor makers gives a fuller picture of national capability. Our UK quantum computing companies guide covers the processor side of that ecosystem.
When adjacent companies matter for your strategy
Procurement and the supply chain
If you build or operate quantum hardware, the adjacent companies are your suppliers, and their roadmaps and lead times directly affect yours. Cryogenics, lasers and fabrication capacity are common bottlenecks, so engaging early with firms like Oxford Instruments and Kelvin Nanotechnology is sound planning. Supply-chain resilience is becoming a strategic concern as the sector scales.
Near-term quantum value
For organisations that want quantum benefits today rather than after fault tolerance arrives, the sensing and security firms are the place to look. Quantum sensors and quantum-safe security are deployable now, with measurable returns in medicine, energy, infrastructure and data protection. These firms offer a practical entry point into quantum technology well before a useful quantum computer exists.
Frequently asked questions
What are quantum-adjacent companies?
Quantum-adjacent companies make the technology that the quantum sector depends on without selling a quantum computer themselves. This covers the supply chain, such as cryogenics, lasers, photonic components and control electronics, as well as the parallel fields of quantum sensing and quantum communication. They use the same physics and talent as quantum computing, and in Britain they form a large and commercially mature group alongside the processor makers.
Who are the leading UK quantum adjacent companies?
The most established is Oxford Instruments, whose cryogenics and fabrication tools sit in quantum laboratories worldwide. Novacene supplies precision lasers, Kelvin Nanotechnology runs a device foundry, and Wave Photonics designs integrated photonics. In quantum sensing the leaders include Cerca Magnetics, QLM Technologies, Delta g and Aquark, while Arqit, KETS Quantum Security and Quantum Dice lead in quantum security, key distribution and random numbers.
Why is the UK strong in quantum-adjacent technology?
Britain combines a deep instrumentation and photonics heritage with a long-running national quantum programme and a strong university base in atomic physics. Oxford Instruments gives the country a global lead in cryogenics, and the National Quantum Technologies Programme has funded sensing and security alongside computing since 2014. The result is a broad enabling layer that reaches market faster than computing, because much of it does not need fault-tolerant machines.
What is quantum sensing and which UK firms lead it?
Quantum sensing uses quantum effects to measure quantities like magnetic field, gravity and time with extreme precision, and it is one of the most commercially advanced parts of quantum technology. In the United Kingdom, Cerca Magnetics builds wearable brain scanners from optically pumped magnetometers, QLM Technologies makes quantum gas lidar for emissions monitoring, Delta g builds gravity gradiometers for surveying, and Aquark develops compact cold-atom systems. These firms sell working products in healthcare, energy and construction today.
How do quantum-adjacent companies relate to quantum computers?
They form one ecosystem, because the processor makers are customers of the adjacent companies. A superconducting quantum computer may run inside an Oxford Instruments refrigerator, use Novacene lasers and rely on chips fabricated by Kelvin Nanotechnology, so a bottleneck in the supply chain slows the whole industry. Tracking the enabling firms alongside the processor makers gives a fuller picture of a country’s quantum capability than a computing-only view.
Which UK companies work on quantum security?
Quantum security in Britain divides into key distribution, random number generation and quantum-safe software. KETS Quantum Security builds quantum key distribution and random number generation onto photonic chips, Quantum Dice produces self-certifying quantum random number generators, and the publicly listed Arqit Quantum delivers symmetric-key quantum-safe encryption as a cloud service. These products help defend against the harvest-now-decrypt-later threat that a future cryptographically relevant quantum computer would create.
Are quantum-adjacent companies a good investment?
Many of the UK quantum adjacent companies reach revenue sooner than processor makers, because cryogenics, lasers, sensors and security products have customers in existing markets today. That gives them clearer commercial models than companies betting on a future fault-tolerant computer, though they remain exposed to the same talent competition and capital constraints as the wider sector. Investors often treat the enabling layer as a lower-risk way to gain exposure to quantum technology.
How can I access UK quantum-adjacent technology?
Most of these companies sell directly to industry and research customers, and several are publicly listed or work through the National Quantum Technologies Programme and the National Quantum Computing Centre. Cryogenics, lasers and fabrication are bought as capital equipment or foundry services, while sensing and security firms offer products and managed services. Organisations usually start by identifying which enabling technology their project needs, then engaging the relevant supplier early because lead times can be long.
