Alice & Bob, leader in fault-tolerant quantum computing, today shared results from implementing GPUs to decode its LDPC-cat architecture using NVIDIA NVQLink. Proof of concept using synthetic data is first time LDPC-cat codes have been decoded on GPUs via low-latency high throughput NVQLink architecture and moves company closer to fast scalable error correction for cat-qubit quantum computers.
NVQLink allows researchers to more easily build hybrid quantum-classical systems accelerating next-generation applications in chemistry and materials science. NVQLink specifically supports tasks that require fast communication between quantum and classical hardware such as error-correction decoding calibration and hybrid quantum-classical applications across any qubit modality.
Alice & Bob assessed feasibility of GPU decoding for LDPC-cat codes using NVQLink connection with Quantum Machines OPX1000 and Open Acceleration Stack modular framework that couples controller directly to GPUs and other classical processors with microsecond-scale roundtrip latency. In particular researchers assessed whether measurement data could be transferred from control electronics to GPU. Though proof of concept and not constituting real-time decoding results show how decoding can scale by becoming more efficient as several syndromes decoded in parallel.
Error correction is what will turn quantum computers into useful machines and decoding is one of its most demanding classical tasks. Showing that our LDPC-cat codes can be decoded on NVIDIA GPUs with existing tools is encouraging for scaling because it means decoding capacity can grow with machine. Next step is making it fast enough to keep pace with quantum computer and working with NVIDIA to get there.
Collaboration builds on existing relationship between two companies. In March 2026 companies announced runtime of 1 hour 57 minutes for decoding of simulated syndrome data of its Elevator Codes with NVIDIA】 CUDA-Q platform. In June 2025 companies announced integration of NVIDIA CUDA-Q into Dynamiqs Alice & Bob QPU simulation library enabling GPU-accelerated quantum simulations.
Major challenge with present day quantum computing is errors build up faster than they can be corrected and traditionally it has been challenge to bring state of art compute to this problem for faster qubit modalities like cat qubits. Alice & Bob work shows how NVQLink can in fact accelerate real-time decoding needed to turn cat qubits into fault tolerant quantum-GPU supercomputers.
Alice & Bob will now optimize pipeline chain of steps that carry measurement data through NVQLink to GPU to enable performance needed for real-time decoding.
About Alice & Bob
Alice & Bob is a quantum computing company based in Paris and Boston whose goal is to create the first universal, fault-tolerant quantum computer. Founded in 2020, Alice & Bob has raised €180 million in funding and employs more than 250 people.
Advised by Nobel Prize winning researchers, Alice & Bob specializes in cat qubits, a technology developed by the company’s founders. Demonstrating the power of its cat architecture, Alice & Bob recently showed that it could reduce the hardware requirements for building a useful large-scale quantum computer up to 200 times compared with competing approaches.
