Experimental Quantum Physicist

You role at C12 Quantum Electronics:

C12 Quantum Electronics is developing a hybrid quantum architecture based on spin qubits in carbon nanotubes, coupled through a circuit quantum electrodynamics (cQED) platform. Our approach combines the exceptional coherence properties of carbon-based qubits with high-connectivity microwave architectures, with the goal of building a fault-tolerant quantum processing unit.

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.

Working at the intersection of quantum physics, engineering, and software, you will collaborate daily with theory and the other engineering teams — all co-located in our Paris lab to make those interactions as direct and continuous as possible.

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!

 

Key responsibilities:

Design, calibrate, and optimize DC and microwave experiments in dilution cryostats equipped with state-of-the-art high-frequency control electronics

Develop scalable measurement and analysis workflows: well-documented, reproducible, and built to run with increasing autonomy

Sustain a close feedback loop with engineering teams to continuously improve device performance

Work closely with the theory team to connect experimental observations with physical models

Actively collaborate with the software team to execute our automation roadmap — from experiment scheduling to data analysis — as we scale toward a full QPU

Deepen our understanding of spin qubits in carbon nanotubes integrated within high-impedance cQED architectures

About you:

You are driven by the scientific and engineering challenge of building a quantum computer, and you want to contribute to a meaningful milestone in the field
You hold a PhD (or Masters with substantial research experience) in quantum physics or a closely related discipline
You have hands-on experience with quantum experiments — DC transport, microwave spectroscopy, or both
You write Python fluently and use it autonomously to control experiments, process data, and build reusable tools
You hold yourself to high scientific standards and are equally motivated by results
You communicate clearly in English, in writing and in conversation, across technical and non-technical audiences

What we offer:

• 55,000 euros - 62,000 euros yearly base salary
• Stock options for every employee (BSPCE/ESOP)
• Sponsored trip to conferences around the world
• A highly dynamic international team
• Swile meal vouchers
• Mental health support with moka.care
• Training budget/ Annual Learning & Development Allowance
• Sabbatical leave (after 2 years in the company)
• Vibrant office culture (two office spaces in the heart of Paris, team lunches, offsite events, Friday breakfasts..)

You should join us if...

• You like hands-on work and technology
• You want to contribute to achieving landmark results in quantum computing, making a difference in the emerging quantum technologies
• You want to work within a team of 80+ people with various backgrounds in nanofabrication, quantum electronics, and carbon nanotube science to create a revolutionary quantum computing processor
• You want to thrive in an exceptional scientific environment with several industrial and academic partners
• You share our values (excellence, scientific integrity, diversity, curiosity, and care) and want to help us define our product-focused culture and ambition to accelerate