Characterization and mitigation of spectator phases on a superconducting multi-qubit device.

Flux pulses are used to implement two-qubit gates by changing the frequency of flux-tunable qubits and/or tunable couplers. However, because of flux crosstalk, these flux pulses can also result in phases being acquired by other qubits on the device that are not being targeted by the active gate, which we call spectator qubits. In this talk, we investigate the behavior of phases acquired by spectator qubits in response to unipolar, bipolar, and parametrically-modulated flux pulses. We demonstrate that, in certain regimes, the spurious spectator phase can be mitigated without adding additional pulses to the two-qubit gate scheme.