Alice & Bob has launched a white paper outlining a clear path to achieving useful quantum computing through its cat qubit technology, which promises to deliver high-fidelity logical qubits while using significantly fewer hardware and energy resources compared to alternative approaches.
The company also revealed a five-year roadmap that details five key milestones in its plan to deliver a universal, fault-tolerant quantum computer by 2030:
- Milestone 1: Master the Cat Qubit – Achieved in 2024 with the Boson chip series, this milestone established a reliable, reproducible cat qubit capable of storing quantum information while resisting bit-flip errors.
- Milestone 2: Build a Logical Qubit – Currently under development with the Helium chip series, this stage focuses on creating the company’s first error-corrected logical qubit operating below the error-correction threshold.
- Milestone 3: Fault-Tolerant Quantum Computing – With the upcoming Lithium chip series, Alice & Bob aims to scale multi-logical-qubit systems and demonstrate the first error-corrected logical gate.
- Milestone 4: Universal Quantum Computing – The Beryllium chip series will enable a universal set of logical gates enabled by magic state factories and live error correction, unlocking the ability to run any quantum algorithm.
- Milestone 5: Useful Quantum Computing – The Graphene chip series, featuring 100 high-fidelity logical qubits, will deliver a quantum computer capable of demonstrating quantum advantage in early industrial use cases by 2030, integrating into existing high-performance computing (HPC) facilities.
“Our roadmap lays out a clear path to solving quantum’s toughest engineering challenges,” says Raphael Lescanne, chief technology officer and co-founder of Alice & Bob. “Quantum computing can seem opaque, but it shouldn’t be. This white paper makes our technology and roadmap accessible for engineers, business leaders and tech enthusiasts alike.”
The white paper, titled “Think inside the box: Quantum computing with Cat Qubits”, outlines Alice & Bob’s endeavors by illustrating how quantum physics enables a richer computing model capable of addressing problems beyond classical computing, including simulations, machine learning and material science. Quantum computing promises transformative applications across industries such as finance, healthcare and cybersecurity.
Achieving practical quantum advantage requires overcoming the errors inherent in quantum systems. Quantum error correction typically relies on additional qubits to detect and correct these errors, but the resource requirements grow quadratically with complexity, making large-scale, useful quantum computing a significant challenge.
Alice & Bob’s cat qubits offer a promising solution to this bottleneck. These superconducting chips feature an active stabilisation mechanism that effectively shields the qubits from some external errors. This unique approach has enabled cat qubits to set the world record for bit-flip protection, one of the two major types of errors in quantum computing, effectively eliminating them.
This protection reduces error correction from a 2D problem to a simpler, 1D problem, enabling error correction to scale more efficiently. As a result, Alice & Bob says it can produce high-quality logical qubits with 99,9999% fidelity, what they call a “6-nines” logical qubit, using a fraction of the resources required by other approaches.
“Quantum computing should be a tool for solving useful problems in science and industry. This white paper shows how Alice & Bob’s cat qubits can bring that vision to life in a practical way by the decade’s end,” says Théau Peronnin, CEO and co-founder of Alice & Bob.