Scientists from Alice & Bob, a quantum computing company, and Inria, France’s national institute for research in digital science and technology, have submitted a new study for peer review. The study details a new quantum error correction scheme, dubbed the “unfolded code,” which presents a method for producing magic states on superconducting quantum computers. This research addresses the challenge of magic state preparation, a resource-intensive aspect of quantum computing necessary for achieving a universal fault-tolerant gate set.
Their new approach, outlined in the paper “Unfolded distillation: very low-cost magic state preparation for biased-noise qubits,” leverages the noise bias of cat qubits, which inherently protect against bit-flip errors. This allows the researchers to “unfold” a complex 3D distillation code into a more hardware-efficient 2D layout. According to the study, this method can produce one magic state with 53 cat qubits, representing an 8.7x reduction in qubit requirements compared to other approaches. The company also estimates an approximate 5x speedup over existing superconducting platforms for the same error rate.
This new scheme is intended to accelerate the path to fault-tolerant quantum computing by reducing the hardware overhead and quantum error correction cycles needed to build a quantum computer. The protocol is designed to use components already required for Alice & Bob’s quantum error correction architecture. The collaboration with Inria supports this research, with a focus on translating these theoretical advancements into experimental demonstrations on hardware.
Read more about this research on the Alice & Bob newsroom here, in the arXiv preprint here, on the Alice & Bob blog here, and review QCR’s previous report on their collaboration with Inria here.
August 6, 2025
