Senior Instrumentalist

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.

C12 is transitioning from a phase of scientific discovery and proof-of-concept demonstrations to one of systematic scaling. This means our focus is shifting towards automation, reproducibility, and process maturity, without sacrificing the scientific rigor and curiosity that got us here.

It is a demanding and exciting moment: we are still making new science, while simultaneously building the infrastructure that will carry us to a quantum advantage demonstration.

The person joining this team will need to be both a rigorous scientist and a pragmatic builder

Your role at C12 Quantum Electronics:

The Qubit Control team sits at the heart of this effort. We develop the methods that make qubits work: tuning protocols, readout strategies, gate implementations. We optimise the control and readout electronics and protocols, explore large parameter spaces, investigate the physics of the spin qubit, and translate physical insight into engineering solutions. We are seeking a skilled Instrumentalist / Metrologist to own the measurement chain.

Key responsibilities:

You are responsible for the error budget of the quantum gates (measurement, monitoring, improvement). You are accountable for the cryogenic DC and microwave control and readout chains whose performance have to be understood perfectly to determine qubit limitations, replicated across multiple identical machines, eventually operating in a data center without a cryogenics expert on site.

Instrumentation and metrology:

• Own the end-to-end signal budget of each cryogenic setup: noise temperature, insertion loss, crosstalk, dynamic range, photon number delivered to the device, calibration of TWPAs, magnetic field measurements.
• In collaboration with the quantum physicists, quantify the impact of noise sources on qubit coherence and operation fidelities, calibrate pulses to optimize qubit readout and gate fidelities, design and test new measurement protocols.
• Design the dashboard to monitor performance metrics of the qubits and setups. Monitor and systematically improve figures of merit, ensure homogeneous performance across the park. Provide structured, quantitative feedback to R&D teams (superconducting resonator design and fabrication, carbon nanotube growth and characterization).
• Drive setup upgrades and new installations from specification through commissioning and acceptance testing, including supplier selection and technical follow-up.

Measurement chain robustness and readiness for scaling:

• Co-design specifications for the integration of the measurement chain, own the qualification and validation chain against agreed system requirements.
• Work closely with Engineering to derive system requirements into technical requirements for the measurement chain of the product, and to define the associated metrology, verification and validation methods.

Transfer and team support:

• Write the documentation that turn your work into shared team capability.
• Train and support quantum physicists and engineers on the setups and the measurement protocols and maintain common standards accross setups.

About you:

• You are driven by the engineering and scientific challenge of building a quantum computer, and you want to contribute to a meaningful milestone in the field.