Demonstration of a high fidelity entangling gate in a superconducting architecture

We demonstrate a high fidelity entangling gate in an architecture of alternating fixed and tunable qubits by directly modulating the flux of the tunable qubit. We achieve this by parking the DC flux of the tunable gate where the qubit is first-order insensitive to 1/f DC flux noise in addition to performing the flux modulated gate at an "AC sweet spot" where the qubit is first-order insensitive to noise under flux modulation, allowing us to leverage a higher ratio of gate time to coherence time. In addition to characterizing the gate using standard protocols, we qualify its performance over long periods of time, self-consistently assessing the gate fidelity and drift therein.