Demonstration of high-fidelity universal gates on a continuously noise-decoupled qubit*

Spin-Locking noise-spectroscopy of quantum systems is a valuable tool in qubit environment characterization. Intriguingly, though, a spin-locked state is itself a continuously noise-decoupled qubit, albeit with a small self-energy. Such spin-locked qubits are insensitive to 1/f noise in the lab frame, and therefore show enhanced long-time frequency stability. The small self-energy, however, makes resonant Rabi driving unsuitable for high fidelity control. We present the implementation and characterization of universal single qubit gates performed on a spin-locked transmon using an alternative control approach.