Absolute Beginner

A company in France built a very special new computer. It is called a quantum computer. It is very different from the computers we use every day at home or school.

The computer uses tiny things called cat qubits. They are named after a famous science story about a cat. These special qubits make fewer mistakes than older types of qubits.

The computer was shown at a big event in Paris on June 17, 2026. France is the first country to have this kind of computer at a national research centre.

Scientists think this computer will one day help solve very big problems. It could help with medicine, climate, and new materials. More work is needed before it can do all of that.

quantum

relating to a very small unit of energy used in physics

qubit

the basic unit of information in a quantum computer

computer

a machine that processes information and performs tasks

error

a mistake made by a machine or person

national

belonging to or involving the whole country

centre

a place where an important activity happens

event

something important that happens at a particular time and place

scientist

a person who studies science and does experiments

Elementary

On June 17, 2026, a French company called Alice and Bob signed an agreement with France's national computing agency, GENCI, to install a quantum computer at a research centre operated by the CEA, a major French science organisation.

The computer has 18 cat qubits. Cat qubits get their name from the famous thought experiment about Schrodinger's cat, a story in which a cat is both alive and dead at the same time until someone checks.

Cat qubits are special because they naturally resist one type of computing error called a bit-flip. A bit-flip happens when a qubit accidentally changes from one state to another. This makes the computer more reliable and easier to correct.

The project is part of France's big plan to lead in science and technology, called France 2030. Scientists at Alice and Bob hope to build a computer with 100 cat qubits by 2028 and a fully working fault-tolerant machine by 2030.

agreement

a decision made by two or more groups to do something together

agency

an organisation that provides a service or manages an area of activity

thought experiment

an imaginary situation used to explore a scientific idea

bit-flip

a type of error where a qubit accidentally switches its state

reliable

able to be trusted to work correctly and consistently

state

the condition something is in at a particular moment

achievement

something accomplished successfully, especially with effort

install

to put a machine or system in place and make it ready to use

Intermediate

France's national supercomputing agency GENCI signed a deployment partnership with quantum startup Alice and Bob on June 17, 2026, at the VivaTech conference in Paris. The agreement places France's first national cat-qubit quantum processor inside CEA's Tres Grand Centre de Calcul (TGCC) facility near Paris and is co-funded under the France 2030 investment programme.

Cat qubits take their name from Schrodinger's famous thought experiment. Unlike standard superconducting qubits, cat qubits encode information in the amplitude of microwave photons oscillating inside a superconducting resonator. This encoding strategy naturally suppresses bit-flip errors, which are one of the two main error types in quantum computing.

The deployed system houses 18 cat qubits, and its bit-flip protection lifetime already exceeds one hour, a significant engineering milestone. Alice and Bob's published roadmap targets 100-qubit performance by 2028 and a fully fault-tolerant architecture by 2030, using the cat-qubit advantage to reduce the overall hardware overhead required for error correction.

France's announcement arrives as global competition in quantum computing intensifies. IBM and Google are advancing superconducting qubit systems under the surface-code paradigm, while Origin Quantum in China recently unveiled the Wukong-180 processor. Microsoft is pursuing topological qubits, and neutral-atom companies such as QuEra and Pasqal offer alternative hardware approaches.

supercomputing

computing performed by the fastest and most powerful machines available

processor

the main chip or unit in a computer that carries out instructions

amplitude

the strength or size of a wave or oscillating signal

resonator

a device that oscillates at a specific frequency to store or amplify energy

fault-tolerant

able to operate correctly even when parts of the system fail

topological

relating to a type of quantum computing that uses exotic quantum states to protect information

logical qubit

a stable, error-corrected qubit built from many physical qubits

superconducting

conducting electricity with zero resistance, achieved at very low temperatures

Advanced

At VivaTech 2026 on June 17, GENCI and Alice and Bob formalised a deployment agreement placing France's first national cat-qubit quantum processor inside CEA's Tres Grand Centre de Calcul (TGCC) near Paris. The project is co-funded by the France 2030 investment plan and sits within the EU Quantum Flagship programme, which aims to position Europe as a global quantum-technology leader by the decade's close.

Cat qubits exploit a bosonic encoding strategy. Information is stored in coherent superpositions of two opposite-amplitude microwave-photon states oscillating inside a superconducting resonator. The symmetry of the two-photon driven dissipative process intrinsically suppresses bit-flip errors. Phase-flip errors must still be corrected by a conventional outer code, but the dramatically reduced bit-flip rate slashes the physical-qubit overhead required for full error correction by roughly one to two orders of magnitude compared with unprotected superconducting qubits.

The deployed 18-cat-qubit system already demonstrates a bit-flip lifetime exceeding one hour, validating the hardware's readiness for scaled error-correction protocols. Alice and Bob's published roadmap targets 100-logical-qubit-equivalent performance by 2028, advancing toward a fully fault-tolerant architecture by 2030. TGCC integration also opens the processor to the French national research community via GENCI's existing high-performance computing allocation mechanisms, broadening scientific access without a separate commercial cloud layer.

The competitive landscape places this announcement within a rapidly maturing global race. IBM's Heron roadmap and Google's surface-code demonstrations on Sycamore pursue high physical-qubit counts under conventional error-correction overhead. China's Origin Quantum Wukong-180 processor follows a similar physical-qubit scaling path. Microsoft's topological qubit programme and neutral-atom platforms from QuEra and Pasqal represent distinct hardware-architectural alternatives. Cat qubits' intrinsic bit-flip suppression offers a potentially leaner route to fault tolerance; whether that advantage compounds at scale - where phase-flip correction overhead and resonator cross-talk become dominant - remains the central open question for the Alice and Bob roadmap.

bosonic encoding

a qubit strategy that stores information in the quantum states of harmonic oscillators rather than two-level systems

coherent superposition

a quantum state combining multiple basis states with definite and stable phase relationships

driven dissipative process

a quantum process that uses continuous external driving and engineered energy loss to stabilise a target quantum state

phase-flip error

a quantum error in which the relative phase between the two basis states of a qubit is reversed

outer code

an additional error-correcting layer applied on top of a hardware-level protection mechanism to handle residual errors