A new partnership between European deep-tech firm C12 and quantum software platform Classiq is poised to accelerate access to scalable quantum computing, announced January 27, 2026. C12, building the next generation of spin qubit quantum processors from ultra-pure carbon nanotubes, is integrating its “Callisto” digital twin – modelling up to 13 noisy qubits – with Classiq’s software. This collaboration aims to bridge the gap between cutting-edge hardware and usable software, allowing developers to design and test algorithms on realistic simulations of future quantum devices. “At C12, we believe quantum computing must move beyond theory and become a practical accelerator for the most demanding computational challenges,” said Pierre Desjardins, C12’s CEO. This integration promises a scalable framework for building and executing quantum applications, future-proofing R&D efforts.
C12’s Carbon Nanotube Spin Qubits Enable Scalable Hardware
C12 is pioneering a novel approach to quantum processing using ultra-pure carbon nanotubes, a nearly one-dimensional material exhibiting record coherence and remarkably low noise levels. This focus on material purity is central to achieving scalable architectures, as it allows for both high qubit quality and robust connectivity—critical for performance as system size increases. The company’s processors leverage spin qubits, fabricated within C12’s quantum fabrication facility in central Paris, which was spun out of research at the École Normale Supérieure. Currently, developers can access a digital twin of C12’s in-development hardware, named Callisto, through integration with the Classiq quantum software platform.
Callisto’s Discovery edition models up to 13 noisy qubits, incorporating realistic noise parameters like charge-noise, phonon noise, and qubit relaxation, alongside features like mid-circuit measurement and noisy initialization. Nir Minerbi, CEO and co-founder of Classiq, added, “Partnering with C12 to integrate an architecture that is dedicated to the highest quality qubits brings exciting new options to quantum developers.” This collaboration aims to align research and development with the capabilities of future quantum hardware.
Classiq Platform Integrates Callisto Digital Twin for Algorithm Design
The Classiq quantum software platform now incorporates Callisto, a digital twin mirroring C12’s developing spin qubit hardware, offering developers unprecedented access to future quantum capabilities. Developers can utilize Classiq’s Qmod language and synthesis engine to design, compile, and test quantum algorithms directly on the Callisto model, proactively aligning research with upcoming hardware specifications. C12’s processors utilize ultra-pure carbon nanotubes, a material achieving record coherence and low noise, crucial for scalable architectures. This collaboration expands Classiq’s support to encompass superconducting, ion-trap, neutral atom, cat, and spin qubit QPUs, alongside simulators from NVIDIA and Intel.
At C12, we believe quantum computing must move beyond theory and become a practical accelerator for the most demanding computational challenges.
Pierre Desjardins, C12’s CEO
Partnership Accelerates Access to Diverse Quantum Processing Units
A strategic integration between C12 and Classiq, announced on January 27, 2026, is poised to expand access to diverse quantum processing units (QPUs) for both enterprise and research sectors. Classiq’s software platform now encompasses leading modalities including superconducting, ion-trap, neutral atom, cat, and crucially, spin qubits—the foundation of C12’s processors. This expansion, alongside access to simulators from NVIDIA and Intel, establishes a scalable framework for quantum application development and execution. The partnership centers on Callisto, C12’s digital twin of its in-development hardware, now supported within the Classiq platform.
