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 are at the forefront of the quantum race, competing with tech giants such as Google or IBM, and we are growing fast after securing €100 million of funding in 2025 to develop our unique technology. Currently 100+ and counting, between physicists, PhD students, engineers and experienced business professionals, we are united to reach our ambitious goal. Are you a quantum pioneer? Join us on a mission to reshape the future! About the role As a Quantum Scientist on the Design & Implementation team, you'll drive the advancement of our cutting-edge cat-qubit processors. You'll also apply your expertise in fundamental quantum physics and quantum mechanics to refine calibration, challenge designs, and optimize our quantum circuits. This role involves designing, modelling, and simulating the behaviour of quantum devices, primarily qubits, to optimise their performance and enable the development of scalable and fault-tolerant quantum computers. Responsibilities

Execute rigorous circuit quantization of dissipative Cat Qubits to define their operational parameters.

Optimize and refine cat qubit circuit designs to enhance system performance and coherence.

Develop high-fidelity experimental models and provide technical troubleshooting to resolve complex lab challenges.

Expand Alice & Bob’s internal knowledge base by documenting novel research and R&D findings.

Communicate key research results through detailed internal reports and external scientific publications.

Requirements

2+ years of experience with quantum device theory and simulation, preferably in the field of superconducting quantum circuits.

Proven experience with specific qubit modalities (e.g., superconducting circuits, trapped ions, semiconductor qubits, topological qubits).

A Ph.D. in Physics, Applied Physics, Electrical Engineering, or a related field with a strong focus on quantum mechanics, condensed matter physics, quantum information, or quantum optics.

Expertise in numerical simulation techniques (e.g., finite element methods, master equation approaches).

Proficiency in programming languages commonly used for scientific computing and simulation, such as Python (with libraries like NumPy, SciPy, QuTiP), MATLAB, or C++.

First-hand experience with Ansys EDT or similar is an asset.

Professional-level English proficiency, both written and spoken.

Nice to Have:

A strong curiosity and openness to new ideas

Research skills (going through existing literature, testing new methods)

Team player mindset

Benefits

Our success is your success : own it with our BSPCE plan

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 under 12 years old children

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 Helium/Axa

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

Recruitment Process

Screening Call with Grace, Talent Acquisition Specialist (30 min)

Hiring Manager Interview with Felix (45 min)

Technical Interview/Presentation with the team (60 min)

Leadership/Fit Interview (45 min)

Reference Check

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. You will join of one of the most innovative startups in France at an early stage, to be part of a passionate and friendly team on its mission to build the first universal quantum computer! We love to share and learn from one another, so you will be certain to innovate, develop new ideas, and have the space to grow.

Quantum Scientist - Device Theory