Thermal Systems Engineer - c12qe

Founded in 2020 and based in the heart of Paris, C12’s mission is to be at the center of one of the biggest technological breakthroughs of the century and change the course of history by building a universal quantum computer.

At C12, we believe that achieving a true breakthrough in quantum computing requires rethinking the fundamentals. That’s why our founders—deeply rooted in academic and engineering excellence—have chosen carbon nanotubes as the building blocks of our quantum processors. This ultra-pure material dramatically reduces error rates, boosts performance, and minimizes hardware overhead—key ingredients for scalable, fault-tolerant quantum computing. By crafting a unique approach that scales, we aim to revolutionize quantum computing just as silicon transformed classical computing.

Since our founding, we’ve raised over €25 million in funding, published 11 scientific papers, and secured 8 patents. Today, our fast-growing team of 80+, including 25 PhDs, has over 26 nationalities represented. We have our own cutting-edge lab spaces in Paris' historic Panthéon district, where scientists, engineers, and innovators work side-by-side to tackle some of the most exciting technical challenges of our time.

If you're passionate about shaping the future of quantum technology and want to make a real impact, C12 offers a unique environment to grow, learn, and innovate.

Your role at C12 Quantum Electronics:

As Thermal Modeling & Cryogenic Systems Engineer (Quantum Hardware) , you will play a central role in enabling the next generation of our quantum computers. You will own the thermal architecture and thermal models of complex cryogenic quantum systems that combine a growing number of qubits with increasingly sophisticated cryo-electronics.

Your work will be critical to ensuring system scalability, thermal stability and quantum performance.

You will operate at the intersection of cryogenics, thermal physics, electronics, and quantum hardware whilst working closely with quantum physicists and engineers.

Key responsibilities:

Develop and maintain system-level thermal models of quantum hardware systems, including qubits, wiring, passive components, and cryo-electronics across all cryogenic stages

Work closely with system engineers and physicists to identify thermal constraints and scaling bottlenecks, evaluate architecture options and guide system design decisions.

Own the thermal budget, including trade-off analysis of different technological options (qubit architectures, wiring schemes, cryo-electronics integration levels, materials)

Own the thermal performance of cryogenic quantum hardware platforms by defining and executing validation experiments, correlating predictions with measurements, investigating discrepancies and implementing solutions to inform thermal and system architecture decisions

Design and evaluate thermalization strategies for signals,