Dynamical Decoupling Shields Qubits From Heavy-Hex Crosstalk

Researchers at the University of Southern California and the Universidad Autonoma de Madrid have demonstrated anisotropic scaling of a surface-code quantum memory on IBM’s Heron-generation superconducting processors. The team moved beyond uniform scaling to achieve codes with distances of (3,5) and (5,3), improving the protection of logical quantum states. This work addresses a central challenge in quantum computing: implementing error correction on hardware where the physical qubit layout doesn’t naturally match the code’s requirements, using a “fold-unfold” embedding and robust dynamical decoupling. The results establish a path toward testing subthreshold surface-code scaling with optimized control on non-native architectures. Achieving subthreshold…