PhD - Quantum Error Correction Codes 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!

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).

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

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,…