All-microwave CZ gate based on fixed-frequency driven coupler

High-quality entangling gates are crucial for scalable quantum information processing. Implementing all-microwave two-qubit gates on fixed-frequency transmons offers advantages in reducing wiring complexity, but the gate performance is often limited due to the residual ZZ interaction and the frequency crowding problem. Here, we introduce a novel scheme that enables a microwave drive-activated CZ gate compatible with the coupler structure to suppress the residual ZZ interaction. The microwave drive is applied to the coupler and the microwave drive frequency remains far detuned from the system’s transition frequency to alleviate the frequency crowding problem. We model the gate process analytically and demonstrate a theoretical gate fidelity up to 99.9% numerically. Our scheme is compatible with current coupler-structure-based circuits, and insensitive to microwave crosstalk, showing a possible path for all-microwave quantum operations at scale.