Building and benchmarking diabatic entangling gates for frequency-tunable qubits, part II

One of the key needs in quantum computing are gates that are fast and precise, requiring precision control and the minimization of leakage out of the computational states. We present the experimental implementation of a synchronization protocol for constructing gates that have minimal leakage and a duration close to the speed limit. Using this method we achieve diabatic iSWAP-like and CPHASE gates with Pauli error rates down to 4.3(2)*10^-3 in as fast as 18 ns with frequency-tunable superconducting qubits. In addition, we show how we use cross-entropy benchmarking (XEB) for quantifying the gates and error budgets.