Guest Post: The UK’s Quantum Ambitions Will Fail Without The Components to Make Them Real

Guest Post by Howard Rupprecht – managing director, CSconnectedIn October 2023, a small British company called KETS Quantum Security completed a successful trial of quantum-encrypted communications on a standard telecoms network. It was a landmark moment providing proof that quantum-secure technology was moving from theoretical physics into deployable infrastructure. The company was spun out of the University of Bristol with photonic chips built from compound semiconductors.Compound semiconductors are the physical building blocks of quantum technology, and without them, the devices that make quantum systems real cannot be built. The UK has committed over £3.5 billion to quantum technologies since 2014, through the National Quantum Technologies Programme and the 2023 National Quantum Strategy. The ambition is bold and well-founded: to be a world-leading quantum-enabled economy by 2033, capturing a 15% share of a global market forecast to reach £137 billion by 2040.

The Industrial Strategy, published last year, goes further still, designating quantum as one of six frontier technologies capable of reshaping the entire economy, and launching five National Quantum Missions spanning computing, sensing, navigation, communications and healthcare.The science is world-class. The policy intent is strong. But there is a question the strategy has yet to answer clearly enough: where will the components that make quantum systems work actually come from? Every quantum device, every secure photon detector, every atomic clock, every quantum sensor, depends on compound semiconductor materials and devices at its core. They are not peripheral to quantum. They are what make quantum physical. And right now, the UK lacks the manufacturing scale to supply them reliably from domestic sources. This major barrier to success is one that South Wales is uniquely positioned to close.The enabling layer quantum cannot do withoutQuantum technologies are sometimes described as if they exist in a realm apart, an exotic science operating at the frontier of human understanding. In one sense, that is true. But the devices that harness quantum behaviour are built from physical materials, manufactured in real facilities, by skilled people. And those materials are, overwhelmingly, compound semiconductors.The dependency runs across every application area the National Quantum Missions are designed to deliver. Quantum-secure communications, the technology KETS demonstrated on a live network, relies on the transmission of individual photons along fibre-optic cables. The single-photon emitters and detectors at the heart of those systems are fabricated from indium phosphide and gallium arsenide, the compoundsemiconductor materials that South Wales has deep, established manufacturing expertise in. Quantum sensors, which promise to transform navigation, subsurface mapping, and medical diagnostics, require semiconductor laser sources to probe precise quantum states in atoms. The atomic clocks that will anchor GPS-independent positioning systems critical for defence, aviation, and financial infrastructure are built around vertical cavity surface-emitting lasers, known as VCSELs, manufactured from compound semiconductor materials. The best performing of these systems lose less than one second over thirty billion years, a precision only achievable with highly stable, commercially reliable semiconductor components.Quantum computers, too, depend on compound semiconductors, not for the quantum processing itself, but for the sophisticated classical electronic systems that control, optimise, and read out quantum information. They are the essential interface between the fragile quantum world and the classical systems that put it to use. This is not a peripheral relationship. As the APPG for Semiconductors set out earlier this year, the impact of quantum technologies will be fundamentally limited by the maturity of the semiconductor supply chain that underpins them. Current quantum demonstrators rely on low-volume, custom materials developed in fragmented supply chains, where economies of scale are poorly defined, and long-term reliability has not been established. Science is advancing. But the manufacturing infrastructure has not kept pace.Where quantum investment becomes economic returnThe case for investing in compound semiconductor manufacturing capability for quantum is not only technical, it’s also economic. The semiconductor industry carries one of the highest value multipliers of any sector in the UK economy, generating £150,000 of gross value added per employee directly within the cluster, and supporting a further £436 million of total Welsh GVA when indirect supply chain and wage effects are included. Every pound of semiconductor revenue earned in South Wales supports additional economic activity well beyond the cluster’s core firms. For every £1 million of GVA generated directly by the cluster, a further £630,000 is supported elsewhere in the Welsh economy. This is not a sector that creates isolated pockets of high-value work. It is one that distributes economic benefit broadly and durably across the region where it has put down roots.Quantum amplifies that multiplier. As the five National Quantum Missions move from funded ambition to deployed reality over the next decade, demand for compound semiconductor components will scale significantly. VCSELs for atomic clocks and quantum sensors, single-photon devices for quantum communications networks, and photonic integrated circuits for quantum computing systems are much more than niche research components. They are the building blocks of a quantum-enabled economy, and the UK currently has no domestic manufacturing base capable of supplying them at scale.In consequence, if that demand is met by overseas suppliers, the economic value of the UK’s quantum investment will accrue elsewhere. If it is met from South Wales, it accrues here. The CSconnected cluster has already demonstrated what ROI on government investment looks like in practice. £850 million invested in facilities, over £150 million in collaborative R&D, 3,140 jobs supported across Wales, and £531 million in annual sales, over 90% of which is exported internationally. These are the returns already generated by a cluster that public co-investment helped to catalyse, and that global companies assessed, trusted, and committed long-term capital to as a result. Since 2020, total Welsh GVA supported by the cluster has almost doubled, growing from £227 million to £436 million in five years.The missing link between quantum science and quantum industryThe science is not the problem. The UK’s quantum research base is genuinely world-class, and the National Quantum Technologies Programme has spent over a decade translating that science into demonstrable applications. The challenge facing the UK is translating that proof of concept into reliable, scalable, commercially available components that quantum system manufacturers can actually build products around.This step requires a semiconductor manufacturing infrastructure that does not yet exist at the scale quantum commercialisation demands. And the consequences of that gap are already visible.The QFoundry programme, a £5.7 million Innovate UK-backed initiative led by the Compound Semiconductor Centre in South Wales, brought together twelve partners, including CSconnected, IQE, Cardiff University, the National Physical Laboratory, Toshiba Europe, and the universities of Cambridge and Sheffield, to establish a national open-access quantum semiconductor device foundry. The project successfully advanced the technology readiness level of key quantum photonic components, including VCSELs and single-photon avalanche detectors, from TRL4 to TRL7. It proved that science could be scaled. But in doing so, it also exposed the structural barrier that sits between proof of concept and commercial production.Quantum photonic components are currently treated as a low commercial priority by volume semiconductor manufacturers, whose production lines are optimised for mass-market applications in electric vehicles and telecommunications. Without dedicated manufacturing capacity structured specifically around quantum requirements, the UK’s quantum supply chain will remain fragmented, low-volume and custom, exactly the conditions that prevent scale, drive up unit costs, and make it impossible for quantum companies to build reliable supply chains around domestic sources.As the APPG for semiconductors has set out, current quantum demonstrators rely on low-volume, custom materials developed in fragmented supply chains where economies of scale are poorly defined and long-term reliability has not been established. The UK has invested heavily in quantum science. It has not yet made the parallel investment in the semiconductor manufacturing capability needed to commercialise it. This gap is visible in unrealised economic potential and strategicvulnerability. A quantum programme dependent on overseas component supply is not a sovereign quantum programme.How to unlock UK growth where it’s already establishedThe intervention the UK needs is concrete, deliverable, and does not require starting from scratch. What is required is a dedicated, commercially scaled, open-access quantum photonic component foundry, not another research demonstrator, but a production-ready facility capable of supplying quantum VCSELs, single-photon emitters, and photonic integrated circuits at the volumes and quality standards that quantum system manufacturers need to build commercial products.South Wales is the only credible location in the UK to deliver this. The cluster already has the integrated infrastructure the intervention requires. IQE provides the epitaxial wafer materials that underpin quantum photonic devices.

The Compound Semiconductor Applications Catapult offers device fabrication, design, test and module integration capability. Cardiff University’s Institute for Compound Semiconductors and Swansea University’s Centre for Integrative Semiconductor Materials provide the academic depth and open-access research infrastructure, with CSconnected acting as the not-for-profit convenor of the cluster, ready to coordinate this activity. The QFoundry consortium has already demonstrated the proof of concept, the partnerships, and the route to scale. The talent pipeline is established and growing.This is not a proposal to build something new. It is a proposal to back something that works. The investment model is well-precedented. When public co-investment established the cluster’s core infrastructure, private capital followed at scale. Vishay committed £250 million to its Newport facility. KLA invested £138 million in an R&D and manufacturing centre. These were not decisions driven by subsidy, they were driven by capability. Global companies assessed what South Wales offered, concluded it was genuinely differentiated, and made long-term commitments accordingly. Targeted public co-investment into a quantum photonic foundry would follow the same logic, and the same return.The window to act is narrowing. Thirty three countries now have national quantum programmes. Private investment is consolidating rapidly into more mature players, and the UK’s largest quantum hardware funding announcements remain ten times smaller than comparable commitments in France and Australia. The risk is not that the UK fails to lead in quantum science. The risk is that it leads in the science and loses the commercial and manufacturing value to nations that moved faster on the infrastructure.The Industrial Strategy has made the right call in designating quantum and semiconductors as co-equal frontier technologies. The practical implication of that designation is simple: investment in one must be matched by investment in the other. South Wales has the cluster, the capability, and the track record. The next step is a national commitment to the foundry infrastructure that turns Britain’s quantum ambition into quantum industry.About CSconnectedCSconnected is a £43 million project focused on expanding the South Wales compound semiconductor industry. As the world’s first compound semiconductor cluster, CSconnected brings together a unique community of academic institutions, prototyping facilities, global high-volume manufacturing capabilities. This collaboration fosters cutting-edge research, innovation and global leadership, positioning Wales and the UK to compete globally in critical sectors such as 5G communications, autonomous and electric vehicles, advanced medical devices, sustainable technology and next-generation consumer electronics.Through strategic collaborations and continuous investment in research and development, CSconnected is committed to maintaining Wales’s position at the forefront of the global semiconductor industry, driving economic growth and technological innovation.​Website: csconnected.comLinkedIn: CSconnectedHoward Rupprecht – managing director, CSconnectedHoward Rupprecht was appointed managing director of CSconnected in March 2024. With over 35 years of experience in the global electronics and semiconductor sectors, Howard combines deep technical expertise with strategic insight into investment, supply chain development, and stakeholder engagement.His career began in electronics manufacturing at Lucas Electronics, before moving into international sales, marketing and business development for advanced production equipment in Silicon Valley. He later held senior leadership roles at VTT Technical Research Centre of Finland, where he specialised in technology commercialisation and ran the Micronova R&D fab, Northern Europe’s largest semiconductor research facility.Returning to the UK, Howard joined Rockley Photonics to build semiconductor supply chain capabilities and now supports cluster growth at CSconnected—helping to attract investment, promoting local, regional, and national economic impact, and raising awareness of the semiconductor industry’s importance.Photo by Ming Jun Tan on UnsplashShare this article:Keep track of everything going on in the Quantum Technology Market.In one place.