A Facile Two-Step Method to Implement NiSWAP and NSWAP Gates in a Circuit QED.

We propose a way for implementing a two-step NiSWAP<inline-graphic></inline-graphic> and NSWAP<inline-graphic></inline-graphic> gates based on the qubit-qubit interaction with N<inline-graphic></inline-graphic> superconducting qubits, by coupling them to a resonator driven by a strong microwave field. The operation times do not increase with the growth of the qubit number. Due to the virtual excitations of the resonator, the scheme is insensitive to the decay of the resonator. Numerical analysis shows that the scheme can be implemented with high fidelity. Moreover, we propose a detailed procedure and analyze the experimental feasibility. So, our proposal can be experimentally realized in the range of current circuit QED techniques. [ABSTRACT FROM AUTHOR]