October 21, 2025 – 9:00am PT
As quantum computing scales toward practical applications, cryogenic I/O systems are emerging as a critical bottleneck. In this joint webinar, FormFactor and Delft Circuits present their roadmaps to address the evolving challenges in cryogenic I/O over the next five years. Building on insights from our previous session, we will explore the increasing complexity of designing and fabricating scalable, high-integrity, and maintainable cryogenic interfaces.
This roadmap is built from the perspective of realizing industrial error-corrected quantum systems: the era of Quantum Advantage. Developing such systems demands for many factors such as high quantity, quality (low error), and reliability. i/o enables this transition by:
Past achievements, present plans and future vision.
Delft Circuits’ roadmap aims to enable fault-tolerant quantum computing by 2030 with i/o dedicated for quantum computing.
The key requirements on i/o are: making many interconnects (10s of thousands) without introducing limiting heat and/or noise to the system.
Delft Circuits’ roadmap shows the timing of i/o system development as well as key product innovations.
“As quantum technology matures, we see the industry evolving from vertically integrated pioneers into an ecosystem built on specialized horizontal layers. Just as control electronics and cryogenic cooling have developed into dedicated layers, i/o is becoming its own domain. Delft Circuits is leading this transformation with Cri/oFlex® — providing the expertise, technology, and services that full-stack companies need to scale faster and more reliably than they could alone. Our roadmap shows how we will continue to strengthen this i/o layer for the quantum industry of today and tomorrow.”
From researchers who need reliable experiments, to engineers pushing toward thousands of channels, to integrators delivering turnkey systems, and decision makers planning for the future.
The number of qubits targeted by the market is increasing rapidly. As each qubit currently requires approximately 3 to 7 control lines, the total number of channels per system is growing at a similar pace. High channel counts are achieved by deploying multiple loaders within a single fridge. Between 2025 and 2026, each loader will support up to 256 channels, and by 2027–2028 this capacity will increase to 1,024 channels per loader. Our roadmap illustrates these developments by visualizing the supported system sizes for fridges equipped with either 6 or 24 loader ports.
In quantum computing, quality is often expressed through two-qubit gate fidelity and, in the future, logical gate error rates. At Delft Circuits, our responsibility is to ensure that the cryogenic i/o never limits qubit performance, even as the number of channels grows. In our roadmap, we focus on minimizing crosstalk to preserve signal integrity. This way, i/o continues to support — rather than constrain — the advancement of quantum systems.
Cri/oFlex® platform and components developed
By re-inventing cabling, from round to planar, from rigid to flexible, from disrupted to monolithic, we have laid the foundation for scalable i/o systems.
With a focus on up-scaling, removing bulky (coaxial) interconnects is key. We have enabled this by launching a high-density, in-line flex-to-coax connector and by introducing direct flex-to-pcb interfacing. Increased density will further be obtained by designing vertical interconnects. For quality, cross-talk will drastically be reduced to enable even the most demanding applications.
Empowering transitions and the final steps towards enabling quantum advantage
The potential of quantum computing stretches beyond the power and speed of classical computers. To achieve these benefits, many qubits with very high-quality need smooth integration without overloading the cryostat. This final phase towards quantum advantage requires i/o excellence.
Qubit-to-qubit connection between different chips
Integrate with optical i/o methods
4.000+ channels per loader towards 10s kQbit systems
Our roadmap touches on many aspects of quantum technology — from qubits and error correction to loaders, chassis, and cryogenic I/O. To make it easier to navigate, we’ve gathered the most important terms and concepts here. Each entry gives a short explanation of what it means and why it matters for scaling. For example, when we speak about a loader, we mean the standardized entry point into a fridge that defines how many channels can be brought into a system. Understanding terms like these helps put our roadmap into context and shows how Cri/oFlex® fits into the broader quantum stack.
The chip is the heart of a quantum computer, where the qubits physically reside. Different architectures exist — superconducting circuits, trapped ions, or spins — each with unique requirements for connectivity. As chips grow in size and complexity, the demand for scalable and reliable I/O grows alongside them.
Quantum processors must be cooled to milliKelvin temperatures to function reliably. A dilution refrigerator (often called a “fridge”) provides this environment, isolating qubits from thermal noise. The design of the fridge, and the number of access ports it provides, directly shapes how many qubits can be controlled.
A loader is the standardized entry point into the fridge for cryogenic wiring. Each loader can house a number of Cri/oFlex® flexes, defining how many channels enter the system. The number of loaders per fridge directly couples to system size: the total number of channels per system.
A quantum motherboard integrates chips and wiring into a modular platform. It provides a base layer that allows processors and subsystems to connect seamlessly. This modularity is a path toward industrial-scale quantum systems.
The QPU is the processing element of a quantum computer, where quantum operations are performed. It contains the qubits and the control structures needed to manipulate them. Just like a CPU in classical computing, the QPU is at the core of execution.
A system refers to the complete setup of a quantum computer. It includes the QPU, cryogenics, I/O cabling, control electronics, and software layers working in harmony. The system-level perspective is crucial for scaling, since bottlenecks often emerge at the interfaces between subsystems.
The stack describes the layered architecture of quantum computing technology. Starting with qubits at the base, it extends through cryogenics, cabling, control electronics, and finally to software.
Cri/oFlex® is Delft Circuits’ flexible, planar cabling solution designed for cryogenics. Unlike coax, which is bulky and hard to scale, Cri/oFlex® uses a monolithic design with multiple lines integrated in a single flex. This enables thousands of channels with low thermal load and high reliability.
I/O is the communication layer between room-temperature electronics and cryogenic qubits. It includes every signal line that drives, tunes, or reads out qubits. As quantum systems scale, I/O becomes a bottleneck. Costs of large I/O systems hold a significant share of about half the budget of a quantum computer.
Cri/oFlex® can include monolithic components like attenuators, low-pass filters, and IR filters. These components are integrated directly into the flex, rather than added as external parts. This reduces points of failure thereby improving reliability, and simplifies fridge wiring and maintenance.
Interfaces are where Cri/oFlex® connects to other technologies, such as PCBs, chips, or coaxial lines. They can be horizontal (edge-launch) or vertical, depending on the architecture.
A line is a single conductor; a channel is one defined signal path; and a flex bundles multiple channels together in a planar, parallel manner. Moving from single-line coax to multi-channel flex is what makes Cri/oFlex® scalable.
A chassis is the modular unit that holds Cri/oFlex® cabling inside a loader. The number of channels per chassis determines the density of connections per fridge port. As systems scale, increasing chassis capacity is a key enabler of higher channel counts.
Multiplexing is a method to send multiple signals through a single physical channel. This becomes vital when the number of physical lines required exceeds what can reasonably be installed in a fridge. It is one of the technologies that will enable large-scale systems.
Cri/oFlex® can be made from different conductor materials, such as silver (Ag) or niobium-titanium (NbTi). NbTi is superconducting at cryogenic temperatures, which minimizes loss and thermal load. The choice of platform depends on the use case and system requirements.
Crosstalk happens when signals interfere with each other across neighboring lines. Noise refers to unwanted disturbances that lower signal fidelity. Both must be minimized to ensure qubits can operate with high quality.
Heat load is the energy carried down into the fridge through cabling. This generates thermal noise, which disrupts qubit operation if not controlled. Managing heat load per channel is essential to maintaining system performance.
Performance refers to the overall effectiveness of the I/O system. This includes fidelity, stability, scalability, and reliability over repeated thermal cycles.
Points of failure are the weak spots in any I/O chain — often connectors or transitions. Identifying and eliminating these points improves reliability. Cri/oFlex® reduces them by integrating filtering components and having a multi-channel design.
These are core measures of qubit quality. Two-qubit gate fidelity reflects how accurately quantum operations are performed. Logical error rates, achieved through error correction, show whether systems can reliably run long computations, pointing toward fault tolerance.
Milestones mark progress points on the roadmap, such as the introduction of new interfaces or higher-density flexes. They provide clarity on what to expect and when. Roadmap milestones also guide alignment across the industry.
Quantum advantage is reached when a quantum computer outperforms classical supercomputers on a meaningful task.
A quantum computer is the full system built to run quantum algorithms. Fault-tolerant quantum computing refers to the ability to run indefinitely without errors, thanks to error correction.
A qubit is the fundamental unit of quantum information, analogous to a bit in classical computing. Today’s systems contain tens to hundreds of qubits, but the field is moving toward thousands (kQubits). Each qubit requires multiple I/O lines, driving scaling demands.
A roadmap shows the planned evolution of technology, aligning industry players around shared milestones. In the quantum industry, roadmaps give confidence to customers, partners, and suppliers about future directions.