Superconducting qubits now switch states in just 10 nanoseconds

Superconducting qubits have significantly contributed towards the development of a universal quantum computer. The team balanced the need for long coherence, reaching up to hours in a ‘heavy’ regime, with simplified control by introducing a qubit architecture featuring real-time tunable bit-flip protection. This approach uses base-band flux-pulses to realize high-fidelity single- and two-qubit gates. The researchers expect this concept of real-time wavefunction control will extend to other hardware-protected qubit designs. Institute of Science and Technology Austria researchers achieved high-fidelity single- and two-qubit gates using base-band flux-pulses lasting approximately 10 nanoseconds, a speed previously difficult to attain without microwave signals. This control method distinguishes their approach to superconducting qubit design, focusing on real-time tunable bit-flip protection as a means of simultaneously maximizing coherence and simplifying control. The team’s qubit architecture balances these traditionally conflicting goals through manipulation of wavefunction overlap and corresponding matrix elements, offering a novel pathway toward more stable and manageable quantum systems. The newly demonstrated control scheme operates in two distinct regimes,…