High-fidelity two-qubit gates with transmon qubits using bipolar flux pulses and tunable couplers.

Here, we present an experimental realization of a high-fidelity 2-qubit controlled-phase gate using superconducting flux-tunable transmon qubits with 99.48% fidelity. We combine advantages of bipolar flux pulses, named net-zero, and a tunable coupler. First, it allows us to lower long-timescale distortions of the flux pulses and make qubit phase insensitive to low-frequency flux noise. Second, the couplers reduce parasitic couplings.