Implementations of more general solid-state (SWAP)${}^{1/m}$ and controlled-(swap)${}^{1/m}$ gates

摘要： Universal quantum gates are the core elements in quantum information processing. We design two schemes to realize more general (SWAP)1/m and controlled-(swap)1/m gates (for integer m 1? ) by directing ?ying single photons to solid-state quantum dots. The parameter m is easily controlled by adjusting two quarter-wave plates and one half-wave plate. Additional computational qubits are not required to construct the two gates. Evaluations of the gates indicate that our proposals are feasible with current experimental technology.