PhD - Quantum Error Correction Codes for Cat Qubits M/F

Alice & Bob is developing the first universal, fault-tolerant quantum computer to solve the world’s hardest problems.

The quantum computer we envision building is based on a new kind of superconducting qubit: the Schrödinger cat qubit ‍⬛ . In comparison to other superconducting platforms, cat qubits have the astonishing ability to implement quantum error correction autonomously!

We're a diverse team of 250+ brilliant minds from over 35 countries united by a single goal: to revolutionise computing with a practical fault-tolerant quantum machine. Are you ready to take on unprecedented challenges and contribute to revolutionising technology? Join us, and let's shape the future of quantum computing together!

The PhD project

Cat qubits exponentially suppress bit-flip errors, which means the error-correcting codes that protect them don’t have to be built like everyone else’s. Designing codes that exploit this noise bias is one of the most direct levers to shrink the hardware cost of a useful quantum computer, and it is exactly what this PhD is about.

The PhD project “Code construction & logic for biased-noise qubits,” one of 15 doctoral projects of QuBriC, the first European MSCA Doctoral Network entirely dedicated to quantum error correction (call HORIZON-MSCA-2025-DN-01-01), bridging classical coding theory and quantum hardware.

Hosted in Alice & Bob’s Error Correction team and supervised by Dr Christophe Vuillot, you will develop high-rate, biased-noise-adapted QEC codes and logical-gate protocols using lifted-product and asymmetric-distance constructions, co-design logical operations, and validate your designs through hardware-in-the-loop simulations and small-scale cat-qubit experiments.

Your results feed directly into Alice & Bob’s roadmap toward a fault-tolerant quantum computer and into the network’s shared QEC-hardware map, including an open online library of codes and logical protocols for biased-noise qubits. Your doctoral degree will be awarded by Sorbonne Université and you will be co-supervised by Mike Vasmer (Inria Paris).

Location & life at Alice & Bob:

You’ll be based in Paris with English as your working language. We offer a hybrid work arrangement, with flexible remote up to 40% a month, and we make space for the rituals that keep us grounded, from Café Cohez on Mondays to Snacky Day on Wednesdays.

As part of the QuBriC training programme, depending on the advancement of the project, you may have 3 secondments:
• Inria (France): fault-tolerant gate protocols and validation under realistic biased noise
• TU Delft (Netherlands): experimental benchmarking and integration of biased-noise gate demonstrations
• University of Navarra (Spain): modelling and simulation of bias-adapted code performance

Responsibilities:

At Alice & Bob you will:

• Develop and benchmark high-rate, biased-noise-adapted QEC codes and corresponding logical-gate protocols using lifted-product and asymmetric-distance constructions
• Co-design logical operations (homomorphic CNOT, transversal Clifford, algorithmic subroutines), incorporating noise bias, connectivity, and measurement constraints
• Validate designs via hardware-in-the-loop simulations and small-scale cat-qubit experiments, quantifying space–time efficiency and logical error suppression
• Benchmark biased-noise performance and decoder compatibility, providing feedback to the network’s architecture and decoder work packages
• Contribute to an open online library of high-rate codes and logical protocols for biased-noise qubits, including analysis of resource overhead, and to open datasets/tools for reproducible biased-noise co-design
• Publish your results in leading journals and present them at international conferences
• Follow the QuBriC doctoral training programme (QEC foundations, coding theory, architectures, decoders, hardware integration), Sorbonne Université doctoral training courses, plus Alice & Bob’s internal courses on biased noise, QEC, and cat qubit hardware
• Carry out the secondments and contribute to the network’s outreach and open-science activities

Requirements (minimum qualifications):

• MSc degree in Quantum Engineering or Physics completed by the recruitment date
• Demonstrated background in quantum information or quantum computing (coursework, thesis, or research projects visible on your CV)
• Proficiency in scientific programming with Python
• Proficiency in English (written and oral)
• MSCA eligibility - doctoral candidate: you must NOT already hold a doctoral degree hat the date of recruitment
• MSCA eligibility - mobility rule: you must not have resided or carried out your main activity (work, studies, etc.) in France for more than 12 months in the 36 months immediately before your recruitment date (short stays such as holidays and compulsory national service are not counted)
• Full-time availability for the 36-month appointment, including the secondments.

We’re also looking for:

• Familiarity with quantum error correction - stabilizer formalism, fault-tolerant logic
• Familiarity with the physics of cat qubits
• Experience with QEC simulation or resource-estimation tooling, and taste for open, reproducible science
• Prior research experience in a quantum computing company or lab (internship, research assistantship)

Salary range:

Employment contract (CDD, 36 months) with Alice & Bob SAS, with full French social security coverage:

• Gross salary 1st year : 37 000 euros
• Gross salary 2nd year : 42 000 euros
• Gross salary 3rd year : 47 000 euros

Benefits:

• Direct IP Compensation: earn substantial bonuses for driving the core patents that define our quantum architecture
• Flexible remote policy, up to 40% a month
• A Parental plan including additional benefits such as crèche support or additional days off to take care of children under 12
• Subsidized membership with Urban Sports Club
• Mental health support with moka.care
• 25-day vacation policy (as per French law) + RTT
• Half of transportation cost coverage (as per French law), or yearly allowance for the die-hard bicycle users
• Competitive health coverage, with Alan
• Meal vouchers with Swile, as well as access to a fully equipped and regularly stocked kitchen
• French language courses covered by the company for those interested

Practical details

• Host institution / employer: Alice & Bob SAS, Paris (Île-de-France)

• Doctoral enrollment: Sorbonne Université

• Supervision: Dr Christophe Vuillot (Alice & Bob), with academic co-supervision under the network’s joint supervision agreements

• Duration : 36 months, full-time

• Expected start date : 01/01/2027

Recruitment process:

Recruitment follows the principles of the European Charter for Researchers and the Code of Conduct for the Recruitment of Researchers: the selection is open, transparent, and merit-based.

1. Please apply with a CV, a motivation letter, academic transcripts, and the contact details of two references.

2. Technical interview with a recruitment committee (60 min)

3. Culture fit interview with our talent acquisition team (30 min)

Others:

The project is funded by the European Union under Grant Agreement No 101312335. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or European Research Executive Agency (REA). Neither the European Union nor the granting authority can be held responsible for them.

Research shows that women might feel hesitant to apply for this job if they don’t match 100% of the job requirements listed. This list is a guide, and we’d love to receive your application even if you think you’re only a partial match. We are looking to build teams that innovate, not just tick boxes on a job spec.

Alice & Bob is an equal opportunity employer committed to diversity, inclusion, and gender balance. We evaluate all applicants on merit, regardless of gender, ethnic origin, religion, age, sexual orientation, or disability. We welcome applications from candidates of all backgrounds and underrepresented groups.