Alice & Bob, a leading quantum computing hardware developer, in collaboration with research institute Inria, has developed a new quantum error correction architecture that significantly reduces hardware requirements for quantum computers. The new architecture uses low-density parity-check (LDPC) codes on cat qubits, enabling the operation of 100 high-fidelity logical qubits with as few as 1,500 physical cat qubits. This advancement could make quantum computers more feasible in terms of time, cost, and energy consumption. Alice & Bob’s CEO, Théau Peronnin, stated that this approach could run Shor’s algorithm with less than 100,000 physical qubits, a 200-fold improvement over competing methods.
Alice & Bob’s Novel Approach to Quantum Computing
Alice & Bob, a hardware developer, in collaboration with research institute Inria, has announced a new quantum error correction architecture. This architecture uses low-density parity-check (LDPC) codes on cat qubits, which could significantly reduce the hardware requirements for useful quantum computers. The theoretical work, available on arXiv, advances previous research on LDPC codes by enabling the implementation of gates and the use of short-range connectivity on quantum chips. This reduction in the overhead required for quantum error correction could allow the operation of 100 high-fidelity logical qubits with as few as 1,500 physical cat qubits.
The Importance of Error Correction in Quantum Computing
According to Jean-François Bobier, Partner and Director at the Boston Consulting Group, over 90% of quantum computing value depends on strong error correction. This is currently many years away from meaningful computations. However, by improving correction by an order of magnitude, Alice & Bob’s combined innovations could deliver industry-relevant logical qubits on hardware technology that is mature today.
The Potential of LDPC Codes and Cat Qubits
The new architecture using LDPC codes and cat qubits could run Shor’s algorithm with less than 100,000 physical qubits. This is a 200-fold improvement over competing approaches’ 20 million qubit requirement, according to Théau Peronnin, CEO of Alice & Bob. This approach makes quantum computers more realistic in terms of time, cost, and energy consumption. Cat qubits alone already enable logical qubit designs that require significantly fewer qubits, thanks to their inherent protection from bit-flip errors.
The Advantages of LDPC Codes
LDPC codes are a class of efficient error correction codes that reduce hardware requirements to correct errors occurring in information transfer and storage. By using LDPC codes on a cat-qubit architecture, this latest work not only shows how the qubit footprint of a fault-tolerant quantum computer could be further reduced but overcomes two key challenges for the implementation of quantum LDPC (qLDPC) codes.
Alice & Bob’s First Logical Qubit Prototype
Alice & Bob recently announced the tape out of a chip that would encode their first logical qubit prototype, known as Helium 1. When logical qubits with a sufficiently low error rate are implemented and using the cat qubit LDPC code technique, Alice & Bob would be capable of harnessing the computing power of 100 logical qubits with as little as 1,500 physical qubits, to run fault-tolerant algorithms.
The Potential of Alice & Bob’s New Architecture
As superconducting quantum computing manufacturers like IBM offer up to 1,121 physical qubits, outperforming classical computers in the simulation of quantum systems (quantum supremacy) is a milestone that would become attainable within current hardware capabilities using Alice & Bob’s new architecture.
About Alice & Bob
Alice & Bob is a start-up based in Paris and Boston whose goal is to realize the first universal, fault-tolerant quantum computer. Founded in 2020, Alice & Bob has already raised 30M€ in funding, hired over 80 employees, and demonstrated experimental results surpassing those of technological giants like Google or IBM. Alice & Bob specializes in cat qubits, a technology pioneered by the company’s founders and later adopted by Amazon. Demonstrating the power of its cat architecture, Alice & Bob recently showed it could reduce hardware requirements to build a large-scale useful quantum computer by up to 200 times compared to competing approaches.