Quantum RF Engineer

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 60, including 20 PhDs, has over 20 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 :Your main responsibility will be contributing to the design & optimization of passive and active on-chip microwave components for qubit control, qubit-qubit interfacing and qubit readout. You would be performing EM and circuit simulations for individual components and integrated systems along with contributions to cryogenic measurements for component and system performance verification.Responsibilities :Design and simulation of DC, RF and microwave on-chip componentsContributing to the cryogenic measurementContributing to the continuous improvement of our python based design repository and integration with simulation workflowOccasional involvement in design of mechanical parts (Fusion 360, SolidWorks…) and PCBs. About you:At least Master's degree in Quantum Physics (preferred), Applied Physics, Electrical engineering, Nanotechnology or Nanoscience or other related disciplinesPrevious experience designing and integrating RF & microwave components and subsystems: Previous electromagnetic simulations using industry standard tools such as HFSS, SONNET, ADS, ComsolHigh-frequency (RF, microwave or mm-wave), IC or PCB designPrevious experience with chip design layout tools like Klayout, L-EditDesign/development in PythonGreat communication in English (verbal and written)A plus to have : Previous experience with cryogenic RF and DC measurement Knowledge of semiconductor device physics and microfabrication processes Knowledge of fabrication principles and the constraints they impose on physical device parametersWhat we offer:Flexible rhythm of remote workStock options for every employee (BSPCE/ESOP)Two incredible office spaces in the heart of Paris (both next to the famous Panthéon!)Sponsored trip to conferences around the worldA highly dynamic international teamSwile meal vouchersBreakfast for all every FridayMental health support with moka.careTraining budgets/ Annual Learning & Development AllowanceSabbatical leave (after 2 years in the company)You should join us if...You want to have a key role in a growing startup with challenges at the frontier of the technologyYou want to contribute to achieving landmark results in quantum computing, making a difference in the emerging quantum technologies. You want to work within a 55-people team 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 partnersYou share our values (excellence, scientific integrity, diversity, curiosity, and care) and want to help us define our product-focused culture and ambition to accelerateC12 encourages all who feel qualified to apply, recruitment decisions are based solely on qualifications, skills, knowledge and experience. Applications from women are particularly welcomed.We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.