Quantum Compilation Intern M/F

Purpose of the role

In a context where magic state preparation dominates the space-time cost of fault-tolerant quantum algorithms, recent advances have substantially widened the factory design space: batched protocols producing several magic states per run, compact protocols leveraging qubit recycling, and “unfolded” distillation performed at the physical rather than the logical level, which exploits the

noise bias of cat qubits.

Because the repetition codes underlying Alice & Bob’s architecture do not natively give access to the full Clifford group, the architecture must also distill Clifford resource states in addition to non-Clifford magic states. Selecting the best factory is a highly multi-parameter optimization problem, coupling spatial and temporal code distances, single- versus multi-output protocols, the degree of parallelism of the distillation circuit, the magic state injection scheme, the factory layout, and hardware connectivity constraints.

The Quantum Compilation Intern helps navigate this design space to identify the most resource-efficient factories for Alice & Bob’s

architecture, focusing first on magic state factories and possibly extending the resulting tools to Clifford state factories.

Reporting to the Quantum Compilation PhD Researcher (CIFRE), with possible co-supervision by Élie Gouzien, they will work closely with the Compilation and QEC teams to design, compile and optimise distillation factories for Alice & Bob’s architecture, and may design new distillation protocols along the way. This work feeds directly into Alice & Bob’s physical resource estimates for (early) fault-tolerant quantum computation.

The internship starts between January and March 2027 !

Responsibilities:

• Review the state of the art in magic state distillation
  • Survey single- and multi-output (batched) protocols, qubit-recycling techniques and unfolded

  (physical-level) distillation

  • Identify promising candidates for Alice & Bob’s architecture, including two-stage strategies

  combining physical- and logical-level distillation

• Compile distillation protocols to Alice & Bob’s logical instruction set
  • Translate selected protocols into sequences of logical operations native to Alice & Bob’s

  architecture

  • Integrate magic state injection schemes and hardware connectivity constraints into the

  compiled protocols

• Design and optimise factory layouts
  • Propose concrete layouts for repetition-code and LDPC-code architectures
  • Minimise factory space-time volume by jointly optimising code distances, degree of paral-lelism and placement of operations
  • Develop resource-estimation and noise-simulation tools
  • Build a tool exploring the multi-parameter design space and computing the space-time cost

  of candidate factories

  • Run circuit-level noise simulations to validate factory output fidelities and refine the resource

  estimates

• Extend the scope and communicate results
  • Design new distillation protocols where the exploration reveals gaps, and apply the developed

  tools to Clifford state factories

  • Document results in an internal report and, where relevant, contribute to publications or

  invention disclosures

Requirements:

You are curious and rigorous, comfortable with open-ended research questions, and able to work independently while engaging regularly with the team.

• Education: Master’s degree (M2) in progress in physics, computer science or quantum

  engineering

• Languages: Proficient in English
• Experience No prior professional experience required; a previous research project or

  internship in quantum information is an asset

• Solid foundations in quantum computing and quantum information, including the stabilizer

  formalism

  • Programming in Python for scientific computing
  • Ability to read and critically assess research literature

  • Rigour, autonomy and clear written and oral communication in English

Nice to have:

• Knowledge of quantum error correction (CSS codes, repetition and LDPC codes, lattice surgery)

and magic state distillation

• Familiarity with classical coding theory
• Experience with stabilizer simulation tools (e.g. stim)
• Experience with combinatorial optimisation or SAT/SMT solvers (e.g. z3)