Hardware
Jülich team runs 6.8-nanosecond single-qubit gates with over 99.98% fidelity
Researchers at Forschungszentrum Jülich (PGI-13 and PGI-8), working with colleagues from Aachen and Cologne, performed two fundamental operations on a single superconducting transmon qubit, each lasting 6.8 nanoseconds. Measured accuracies were 99.981% and 99.989%, and the chance of the qubit leaking to a higher energy state stayed below 0.002% per operation. The team developed a pulse-shaping method called R2D, which builds on the DRAG technique and, according to the researchers, cuts unwanted multiphoton transitions by a factor of more than 20. The work appeared in Nature Communications on 23 October 2026, and the qubit was fabricated at the Helmholtz Nano Facility as part of the QSOLID project.
Why it mattersQubits hold their quantum states for a limited time, so faster gates allow more operations in that window, which matters for complex algorithms and error correction. The method has so far been tested only on one isolated qubit, and further experiments are needed to show whether it works in larger processors and in two-qubit operations.