Characterization and Tuneup of High-Fidelity Two-Qubit Operations on a Parametrically Driven Gate

Maintaining the fidelity of single- and two-qubit gates is a necessary requirement for building a quantum computer, especially in the NISQ era where every gate is critical. At the ideal limit without coherent or systematic errors, the gate fidelity fluctuates as T₁ fluctuates. It is important to be able to characterize the timescales over which system parameters may fall out of calibration, and the worst-performance cases should be reported. Here we present our work towards characterizing these effects, and we compare schemes for automating the recalibration process on a device consisting of fixed-frequency transmon qubits with a tunable coupler. The coupler is parametrically driven to selectively perform an iSWAP or CZ gate. Our results indicate that we are primarily limited by incoherent errors with single-qubit gates performing with >99.9% fidelity and two-qubit gates with fidelities >99.0%.