  Sideband transitions have been shown to generate controllable interaction
between superconducting qubits and microwave resonators. Up to now, these
transitions have been implemented with voltage drives on the qubit or the
resonator, with the significant disadvantage that such implementations only
lead to second-order sideband transitions. Here we propose an approach to
achieve first-order sideband transitions by relying on controlled oscillations
of the qubit frequency using a flux-bias line. Not only can first-order
transitions be significantly faster, but the same technique can be employed to
implement other tunable qubit-resonator and qubit-qubit interactions. We
discuss in detail how such first-order sideband transitions can be used to
implement a high fidelity controlled-NOT operation between two transmons
coupled to the same resonator.
