Qutech played a key role in taking silicon spin-qubit technology from lab to fab. Intel is acquiring Israeli quantum software company Classiq to become a full-stack quantum computing provider by combining the technology with its existing quantum software, silicon spin-qubit technology and semiconductor manufacturing capabilities. The company ultimately wants to add quantum processing units (QPUs) to its portfolio of CPUs, GPUs and other computing chips. Classiq develops software that automatically translates high-level descriptions of quantum algorithms into optimized quantum circuits. Much like electronic design automation (EDA) software abstracts the complexities of conventional chip design, the Israeli platform allows developers to create quantum applications without having to specify every operation at the hardware level. The software is compatible with different types of quantum processors. Intel intends to maintain that hardware-agnostic approach, but its own quantum bet is focused on silicon spin qubits, a technology that matches well with the firm’s decades-long expertise in semiconductor manufacturing. “For more than a decade, Intel has made remarkable progress in quantum computing by applying its semiconductor innovation, advanced manufacturing prowess and systems engineering expertise to the development of scalable silicon spin-qubit technology,” says Intel CEO Lip-Bu Tan. Tan isn’t being overly generous to a longstanding Dutch partner: Delft-based Qutech, with which the chipmaker entered into a long-term research partnership in 2015. Co-founded by Delft University of Technology and TNO, the institute made key contributions to the advance of spin-qubit technology. Low temperatures In 2022, the partners demonstrated the fabrication of silicon spin-qubit structures in Intel’s D1 manufacturing facility in Oregon. Using 300mm wafers and industrial transistor manufacturing techniques, the researchers produced more than 10,000 arrays containing multiple quantum dots per wafer, with yields exceeding 95 percent. The results, published in Nature Electronics, demonstrated that silicon qubit structures could be manufactured using industrial semiconductor production processes rather than laboratory-scale fabrication methods. The collaboration also produced Horse Ridge, a cryogenic control chip introduced in 2019 and further developed in subsequent years. Quantum processors operate at extremely low temperatures, but controlling large numbers of qubits using conventional electronics outside the refrigerator requires an impractical number of electrical connections. Horse Ridge addresses this wiring bottleneck by moving control electronics closer to the qubits, where they can operate at cryogenic temperatures. Intel released a 12-qubit silicon quantum chip in 2023. Tunnel Falls was mainly intended for the research community. Credit: Intel In 2023, Intel and Qutech renewed their partnership beyond 2025, shifting its primary focus toward cryogenic CMOS electronics. Scientific leadership of the collaboration passed from spin-qubit expert Lieven Vandersypen to TU Delft professor Fabio Sebastiano, whose research focuses on integrated circuits operating at extremely low temperatures. Large numbers Intel now wants to complement this hardware foundation with Classiq’s software technology. The acquisition represents an expansion from developing and manufacturing quantum processors and their control electronics toward providing the tools needed to program and use them. The commercial challenge remains considerable. Although Intel has demonstrated industrial fabrication of silicon spin-qubit structures, manufacturing large numbers of quantum dots isn’t the same as operating a large-scale, fault-tolerant quantum computer. Qubit fidelity, interconnections, control electronics and error correction all remain major obstacles. Classiq’s software could help developers manage increasingly complex quantum circuits, but it doesn’t eliminate those hard