Scaling quantum computers has always run into the same wall: the electronics that control qubits sit outside the refrigerator, at room temperature, while the qubits themselves sit inside at temperatures colder than outer space. Lausanne-based Rhonexum is directly addressing this cabling bottleneck by designing integrated circuits that operate at temperatures near absolute zero, below 4K, placing control electronics closer to the qubits inside the refrigerator.
In March 2026, Rhonexum raised $1 million in pre-seed funding led by QDNL Participations, with participation from Venture Kick and additional support from Swiss innovation programs including EPFL Startup Launchpad, Fondation pour l’Innovation Technologique, and the Swiss National Science Foundation. For a startup that was only founded in November 2025, this combination of equity and grant backed funding signals strong early institutional confidence in both the team and the problem they are solving.
The Cabling Problem:
Today’s quantum computers require thousands of coaxial cables running from room temperature control equipment into a dilution refrigerator. Each qubit needs its own dedicated wire. The longer these cables get, the more heat and signal loss they introduce, eventually distorting signals to the point where qubits cannot be controlled reliably. Adding more qubits under this architecture means adding more cables, more heat, and more complexity. That is not a path to commercial scale.
Rhonexum’s approach is to design components using standard semiconductor processes that operate directly within cryogenic environments, bringing control electronics closer to quantum processors to reduce system complexity and enable more compact and efficient architectures. The difference in practice is significant: rather than routing hundreds of cables from outside the fridge, one cable connects the computer to a cryogenic integrated circuit placed inside the refrigerator alongside the qubits.
The RX-IC Roadmap:
Rhonexum’s first product is the RX-IC, a cryogenic integrated circuit built around three development phases: power management, control, and readout. Each phase builds on the last, so the team can validate and iterate in stages rather than attempting to deliver everything at once.
Rhonexum plans to deliver its first industrial-grade cryogenic product to a select group of early customers by late 2026. The product targets multiple quantum computing architectures including superconducting, spin, photonics, and trapped ion systems. The company also identifies deep space exploration and high sensitivity sensing as additional application areas where electronics must operate under extreme thermal conditions.
The Team Behind it:
Rhonexum was founded by Vicente Carbon and Dr. Hung-Chi Han as a spin-out from AQUA Lab at EPFL. Dr. Han is an expert in cryogenic semiconductor physics and transistor modelling, with published research in the field, and previously worked at TSMC on advanced semiconductor nodes. Carbon specialises in robotics and systems engineering with a focus on translating research into industrial application.
That combination matters here. The startup’s leadership bridges Dr. Han’s background in cryogenic transistor modeling with Carbon’s expertise in systems engineering to connect academic research with industrial-scale quantum deployment. DeepTech startups often stall at the point between lab and product, and having someone specifically focused on that handoff is a structural advantage.
Simulation Before Fabrication:
One part of Rhonexum’s approach that stands out is its software layer. The company uses a software-driven modeling methodology that enables accurate cryogenic simulation before fabrication, allowing for faster and more cost-effective hardware development. This is the RX-MODEL, a cryogenic circuit simulation tool that Rhonexum makes available to partners.
Simulating behavior at cryogenic temperatures before committing to a silicon run reduces cost and iteration time. For a startup working with standard CMOS manufacturing processes, this also opens a path to reaching customers faster without needing a proprietary fab.
Why This Matters Now
Quantum computing research has been scaling up investment across Europe and North America over the past few years. The gap between two qubit laboratory demonstrations and commercially useful machines in the range of tens of thousands of stable qubits remains large, and cryogenic CMOS electronics are widely recognized as one of the core infrastructure pieces needed to close it.
The new funds will be used to accelerate product development, expand the company’s design team, and deliver a first industrial-grade cryogenic electronics product to a limited group of early customers later this year. For teams building or evaluating quantum hardware, Rhonexum’s progress toward scalable quantum computing infrastructure is worth following closely.
Rhonexum is at a specific and well-defined point in the quantum stack: the hardware layer that makes scaling physically possible. That is a concrete place to build, and the team has the technical foundation and early institutional backing to move forward on it.
