Quantum Software Engineer - QEC in London

Infleqtion is a global quantum technology company solving the world’s most challenging problems. The company harnesses quantum mechanics to build and integrate quantum computers, sensors, and networks. From fundamental physics to leading edge commercial products, Infleqtion enables “quantum everywhere” through our ecosystem of devices and platforms. Our mission is to commercialise atom-based quantum products that provide orders of magnitude improvements in performance and computing applications.

Infleqtion has offices in the USA, United Kingdom and Australia. This is a full-time position in our Kidlington and Harwell offices. Our flexible working policy enables all full-time employees to work up to 2 days a week from home as work permits.

Infleqtion is seeking a Quantum Error Correction Specialist to design, analyse, and implement fault-tolerant architectures that enable scalable, high-fidelity quantum computation. In this role, you will develop and evaluate error-correcting codes, decoding algorithms, and fault-tolerant gate constructions tailored to our hardware platforms, translating theoretical QEC frameworks into experimentally realizable protocols. You will work closely with hardware, control, and compiler teams to model noise processes, optimize syndrome extraction and decoding performance, and define logical performance metrics that inform system design. The ideal candidate brings deep expertise in quantum information theory and fault tolerance, strong analytical and simulation skills, and the ability to bridge theory and implementation to advance the reliability and scalability of next‑generation quantum systems.

Job Responsibilities

• Identify and pursue research that advances the understanding of QEC theory, techniques, and implementation in experimental quantum computing devices.
• Develop and optimize QEC protocols tailored to experimental gate‑based quantum computing devices, with a primary focus on neutral atom platforms.
• Use mathematical models and numerical simulations to analyse the behaviour and performance of QEC protocols.
• Develop and implement custom QEC decoders.
• Contribute to the identification and mitigation of noise processes in quantum systems.
• Collaborate with experimental physicists and software engineers to bridge the gap between theoretical concepts and practical implementation.
• Communicate and interpret cutting‑edge research in both theory and experiment with colleagues.
• Engage with the broader scientific community by publishing research findings in scientific journals and presenting at conferences.
• Stay up to date with the latest developments in QEC and related fields.
• Provide guidance and support to other team members, fostering a collaborative research environment.

Qualifications

• PhD in theoretical physics, mathematics, computer science, or another field closely related to quantum information science.
• 2+ years of postdoctoral experience (or industry equivalent) in QEC is highly preferred.
• Experience in tailoring error‑correcting codes for quantum computing devices, and bridging the gap between theory and experiment.
• Strong scientific publication record.
• Proficient in scientific computing.
• Demonstrated ability to work and communicate with all levels of an organization; Professional‑level communication skills, including verbal, written, and presentation skills.
• Demonstrated ability to work comfortably in a highly collaborative, cross‑functional, team‑oriented, and matrixed environment.
• Desire and demonstrated ability to thrive and produce results in a fluid, dynamic, and fast‑paced environment.
• Demonstrated ability to learn new and complex topics quickly.
• Resourceful problem‑solver who collaboratively identifies effective paths forward with demonstrated expertise in executing productisation efforts.
• Passion for solving complex problems and challenges in a highly technical and scientific environment.

Desirable Skills or Knowledge

• Experience with machine learning based decoder algorithms.
• Experience collaborating with hardware engineers to develop decoder technology.
• Familiarity with neutral atom‑based hardware, gatesets, noise models etc.

Equal Opportunity

Regardless of your interest in the quantum industry, you can take pride in the fact that Infleqtion is building an ecosystem of quantum technologies and commercial products, driving the industry towards the future. Studies reveal that while men apply for jobs when they meet an average of 60% of the requirements, women and other groups tend to apply only when they meet all the criteria. If you believe you have the potential but don't meet every single point in our job advertisement, please don't hesitate to contact us! We would love to chat with you and see how you could bring great value to our team. Our goal is to find exceptional individuals who can enrich our team culture, actively contribute, and have a genuine passion for their work. Here you have freedom to embrace your whole self: who you love, your gender identity and expression, skin colour, age, appearance, disability, neurodiversity, DNA, military/veteran status, citizenship, and other factors that make up who you are. Your uniqueness is valued, welcomed, and appreciated here. We are dedicated to providing a positive workplace and base all employment decisions on your qualifications, performance, merits, as well as business needs. We are proud to be an Equal Employment Opportunity Employer.

In addition to your base compensation, we offer a generous Total Rewards program which includes:

• Competitive salary.
• Incentive Stock Option Plan.
• Generous company 10% pension contribution regardless of employee contribution.
• Unlimited PTO.
• BUPA healthcare after probation period.
• Cycle to work and Technology scheme.