Alice & Bob Reports PROQCIMA Phase 1 Results

French quantum computing company Alice & Bob says it has demonstrated each building block of a cat-qubit logical qubit during the first phase of PROQCIMA, France’s state quantum programme. But by its own account, the logical error rate it measured was “not yet below threshold”, the point at which error correction starts to suppress errors rather than add to them. The results were set out in a company press release on 20 October 2026.

These are company-reported results and have not been peer reviewed. The French state has not published its own assessment of Phase 1. Even so, the release offers a rare look at how one of the five competitors is progressing in a defence-led programme that aims to deliver large error-corrected machines by 2032.

In brief

Alice & Bob says it showed each building block of a cat-qubit logical qubit on three demonstrators, two with 6-qubit chips and one with a 12-qubit chip.
The company reports a logical error rate “not yet below threshold”; it says a digital twin shows improvements are needed, starting with qubit coherence.
The results are Alice & Bob’s own summary and are not peer reviewed; the state has not published its assessment of Phase 1.

What PROQCIMA is

According to the release, PROQCIMA is “Led by the French Defense Innovation Agency (AID) and the Direction générale de l’Armement”. It “aims to develop two prototypes of universal quantum computers, each capable of supporting 1,000 logical qubits, ready for industrialisation by 2032.”

It is structured as “a 10-year competition: three candidates will continue after the first four years, with two ultimately selected to continue beyond year eight.” Five companies were selected: Alice & Bob, Pasqal, Quandela, Quobly and C12. The first phase was designed to assess the technical and industrial feasibility of each approach, including tests on real hardware.

Alice & Bob says it began Phase 1 in 2024, committing to build an integrated multi-block demonstrator with partial functional validation. It says it “has delivered on that commitment”. The release does not say whether it will be among the candidates that continue.

What Alice & Bob says it demonstrated

The company says it assembled and operated “three independent demonstrators, two on 6-qubit chips and one on a 12-qubit chip”. It lists several results. These include noise-biased CNOT gates between cat qubits that preserve their built-in protection against bit flips, and a measure-and-reset sequence for auxiliary qubits, “with performance broadly in line with programme targets”.

It also reports “Multiple cycles of a three data qubit (distance-3) repetition code”, the smallest code able to correct a quantum error. It measured the logical error rate across the full register, “achieving a logical error rate not yet below threshold”. Finally, it demonstrated “A non-Clifford gate on a cat qubit”, which it calls a first step towards producing the “magic states” that universal fault-tolerant machines need.

Alongside the hardware, Alice & Bob built a digital twin of its processor from measured data. Simulations show the improvements needed to operate below threshold, “starting with extending qubit coherence consistently across the chip”.

Keeping qubits calibrated

The demonstrators were supervised by MnR, Alice & Bob’s own monitoring and recalibration software. Running around the clock when the processor was idle, it measured “more than 50 indicators per qubit” and flagged when a qubit drifted and needed recalibration. Previously, the company says, detecting and correcting drifts “could cost up to a day of operating time.”

“The race for fault-tolerant quantum computing is a question of who will master one of the defining technologies of this century, and France starts from a position of real strength,” said Théau Peronnin, Alice & Bob’s chief executive. He said the Phase 1 results “show that the cat qubit approach, combined with Alice & Bob’s expertise, can lead that race”.

Founded in 2020 and based in Paris and Boston, Alice & Bob says it has raised €180 million and employs more than 250 people.

Our read

Showing every building block on real chips is meaningful progress for cat qubits, which aim to cut the hardware needed for error correction. But the key number, the logical error rate, is not yet below threshold, so this is not yet working error correction. With the state’s own verdict unpublished, the real signal will be whether Alice & Bob is among the three candidates that continue after the programme’s fourth year.