  Implementation of high-fidelity swapping operations is of vital importance to
execute quantum algorithms on a quantum processor with limited connectivity. We
present an efficient pulse control technique, cross-cross resonance (CCR) gate,
to implement iSWAP and SWAP operations with dispersively-coupled
fixed-frequency transmon qubits. The key ingredient of the CCR gate is
simultaneously driving both of the coupled qubits at the frequency of another
qubit, wherein the fast two-qubit interaction roughly equivalent to the XY
entangling gates is realized without strongly driving the qubits. We develop
the calibration technique for the CCR gate and evaluate the performance of
iSWAP and SWAP gates The CCR gate shows roughly two-fold improvement in the
average gate error and more than 10~\% reduction in gate times from the
conventional decomposition based on the cross resonance gate.
