Development of Tuxedo: a super-conducting flex-to-pcb interface connection for quantum technologies

Project Information

Tuxedo

Grant agreement ID: 101218253

DOI

10.3030/101218253

EC signature date 5 August 2025

Start date 1 September 2025

End date 31 August 2027

Funded under

• The European Innovation Council (EIC)

Total cost

No data

EU contribution

€ 2 499 999,00

Coordinated by

DELFT CIRCUITS B.V.
Netherlands

Periodic Reporting for period 1 - Tuxedo (Development of Tuxedo: a super-conducting flex-to-pcb interface connection for quantum technologies)

Reporting period: 2025-09-01 to 2026-08-31

Summary of the context and overall objectives of the project

Quantum computers promise transformative computing power, but nearly all current architectures need to be cooled to extremely low temperatures — a few hundredths of a degree above absolute zero — to operate reliably. Connecting these ultra-cold quantum chips to the room-temperature electronics that control them requires many electrical connections that must reach from room temperature down to the coldest point of the system without introducing heat, electrical crosstalk, or signal loss. As quantum computers scale from tens to potentially tens of thousands of qubits, this input/output (I/O) wiring has become one of the key bottlenecks limiting further progress, a challenge increasingly recognised across the quantum technology industry.

The TUXEDO project addresses this by developing a superconducting, high-density connector interface that links the ultra-thin superconducting cables used inside a quantum computer's refrigerator to the circuit boards carrying signals further into the system. By making this connection smaller, more reliable and easier to manufacture at scale, TUXEDO aims to enable the ten-fold increase in usable channels needed to move from today's small-scale quantum processors toward systems with thousands of qubits.

Delft Circuits, the project coordinator, is a European deep-tech company specialised in cryogenic I/O solutions for quantum computing. Solving this bottleneck is not only a technical challenge but a strategic one for Europe: reliable cryogenic components are a critical link in the global quantum supply chain, and strengthening European capability here supports the continent's ambitions for technological sovereignty in quantum technologies. If successful, TUXEDO's results are expected to benefit quantum computing developers, cryostat manufacturers and research institutes worldwide.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Over the reporting period, the project team designed, built and tested several generations of the TUXEDO connector interface, progressively improving its electrical performance and mechanical reliability. Prototypes were validated through measurements at both room temperature and cryogenic conditions, focusing on two key metrics: minimising unwanted electrical interference between neighbouring signal channels ("crosstalk") and ensuring a stable, low-resistance electrical connection. Through improved manufacturing processes and refined mechanical design, crosstalk performance was improved substantially compared to the initial prototype, reaching levels suitable for demanding quantum computing applications, and the interface was successfully integrated into a complete cryogenic wiring chain that met the project's technical requirements.

The connector was also field-tested by two independent quantum technology companies in their own operational systems — one developing spin-qubit technology, the other working on cryogenic detectors. This real-world testing confirmed reliable performance and surfaced valuable practical feedback that is now shaping further improvements to the design.

In parallel, the team improved the manufacturing process for the underlying superconducting cable technology and expanded its in-house cryogenic testing capabilities, strengthening the foundation for the remainder of the project.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The results achieved represent a meaningful advance over the state of the art in cryogenic I/O technology for quantum computing. Commercially available cryogenic wiring solutions today are typically limited in channel density and require multiple connector interfaces along the signal path, each adding electrical loss, crosstalk and assembly complexity. The TUXEDO interface reduces the number of these connection points while achieving crosstalk performance suitable for the increasingly stringent requirements of next-generation quantum processors, in a compact, high-density form designed for scalable manufacturing.

Field validation with two independent end-users, in different quantum technology applications, goes beyond simple laboratory demonstration: it shows the technology works reliably across the varied, real-world conditions of different quantum computing platforms, and has surfaced practical lessons directly shaping the next generation of the technology.

To fully translate these results into a widely deployable product, further work is needed on standardising the interface across different hardware configurations, further improving long-term reliability under repeated use, and scaling up manufacturing capacity to meet growing industry demand. Continued collaboration with quantum computing developers, cryostat manufacturers and other supply-chain partners will be important to ensure wide adoption.