Xanadu, a full-stack photonic quantum computing company, and imec are partnering to develop the next generation of quantum qubits based on ultralow-loss silicon nitride waveguides. A SiN wafer with photonic integrated circuits manufactured on imec’s advanced 200-mm line. Courtesy of imec. Xanadu is developing a quantum computer based on photonic qubits. Specifically, these photonic qubits are based on squeezed states — a special type of light generated by chip-integrated silicon photonic devices. This approach uses particles of light to carry information through photonic chips, rather than electrons or ions used by other approaches. Xanadu’s photonic approach offers the benefits of scalability to one million qubits through optical networking, room temperature computation, and the ability to leverage fabrication R&D centers such as imec. Competing platforms for photonic quantum computing traditionally rely on single-photon sources made from silicon waveguides, which suffer from nondeterministic operation. Using silicon nitride enables the generation of squeezed states, which replace single photons as the basic resource for synthesizing qubits. Squeezed states are deterministically generated and can be used to distill error-resistant qubits called GKP states. When multiplexed and implemented in Xanadu’s architecture, they offer a more promising path to fault-tolerant computing. “Imec is one of the few semiconductor R&D centers that does advanced technology R&D on advanced 200-mm and 300-mm lines, as well as volume manufacturing on their 200-mm line, capable of delivering up to a thousand wafers per year per customer on a few platforms including ultralow-loss photonic platforms,” said Zachary Vernon, who heads Xanadu’s hardware team. “The seamless transfer offered by imec of new processes to production is especially critical for rapid scaling of our technology.”