A 48-qubit code supports fully addressable quantum phase control

Researchers at the International Quantum Academy and the National University of Singapore have constructed a 48-qubit code supporting fully addressable transversal T gates, a critical component for building practical, error-corrected quantum computers. The work improves existing guarantees for controlling quantum phase, using a novel cyclic encoding that separates logical phase control from the design of code rate and distance. This approach yielded a performance improvement by a factor of approximately 2.86, and establishes an upper bound only 1.28 times greater than the lower bound achieved by this construction. These results provide concrete targets for advancing efficient quantum code designs. A deterministic construction now establishes a lower…