Quantum gates set speed record at 6.8 nanoseconds with over 99.98% accuracy

Record‑breaking quantum gate speed

A team from the Peter Grünberg Institute at Forschungszentrum Jülich has demonstrated elementary quantum operations on a superconducting transmon qubit in just 6.8 ns—roughly the time light travels two metres. The two gates they tested achieved 99.981 % and 99.989 % fidelity, and the probability of the qubit leaking to higher energy levels stayed below 0.002 % per operation. These numbers set a new benchmark for how fast and how accurately a quantum gate can be performed.

Why speed matters in quantum computing

Superconducting qubits retain coherence for only a limited window, typically on the order of microseconds. Within that window, every nanosecond counts: faster gates allow more operations before decoherence erodes the quantum information, which is essential for running complex algorithms and for implementing error‑correction protocols. However, accelerating a gate usually means applying stronger microwave pulses, which can unintentionally excite the qubit into non‑computational states (the so‑called leakage or multiphoton transitions).

The R2D pulse‑shaping solution

The Jülich group tackled the leakage problem by extending the well‑known DRAG (Derivative Removal by Adiabatic Gate) technique. Their new method, dubbed R2D, sculpts the frequency spectrum of each microwave pulse so that components capable of driving unwanted transitions are heavily suppressed—much like a filter that blocks specific notes while letting the desired tone pass. In practice, R2D reduced the incidence of multiphoton leakage by more than a factor of 20 compared with standard DRAG, while still delivering the ultra‑short 6.8‑ns pulse.

Experimental context and next steps

The experiments were carried out on a single transmon qubit fabricated at the Helmholtz Nano Facility, as part of the larger QSOLID collaboration. While the single‑qubit results are compelling, the method has yet to be validated on multi‑qubit processors or for two‑qubit entangling gates, which are the workhorses of scalable quantum algorithms. Future work will need to confirm that the R2D shaping scales without introducing cross‑talk or additional calibration overhead.

Practical implications

If the technique proves robust in larger systems, it could reshape the design trade‑offs for superconducting quantum computers. Engineers would no longer have to choose between speed and fidelity; instead, they could push gate times into the sub‑10‑ns regime while keeping error rates well below the thresholds required for fault‑tolerant quantum error correction. This would accelerate progress toward practical quantum advantage in fields such as chemistry simulation, optimization, and cryptography.

--- The findings were reported in Nature Communications (2026) and represent a collaborative effort between experimentalists and theorists at Jülich, Aachen, and Cologne.