Local Decoupling Cancels Interactions Without Exponential Overhead

Researchers have developed a framework to construct shorter and more efficient quantum decoupling sequences by bridging concepts from classical error correction and graph theory. The approach tackles residual “ZZ and ZZZ interactions” in superconducting qubits, a major hurdle to building stable quantum computers, by enabling customized sequence construction that selectively cancels specific unwanted connections without incurring the exponentially growing sequence lengths of traditional methods. This innovation exploits symmetries within extending graph-coloring strategies to complex many-body Hamiltonians and overcoming exponential overheads. The resulting protocols are tailored to a device’s specific connectivity and noise, with sequence lengths that avoid exponential…