One-step achievement of robust multipartite Greenberger-Horne-Zeilinger state and controlled-phase gate via Rydberg interaction

摘要

We present a proposal for generation of a robust tripartite Greenberger-Horne-Zeilinger state among three individual neutral Rydberg atoms. By modulating the relation between two-photon detuning and Rydberg interaction strength U_(ij)(r), an effective Raman coupling is obtained between the hyperfine ground states |F =2, M = 2> of three ~(87)Rb atoms and the Rydberg states jrrri via the third-order perturbation theory. This method is also capable of implementing a three-qubit controlled-phase gate with each qubit encoded into the hyperfine ground states |F = 1, M = 1> and |F = 2, M = 2>. As an extension, we generalize our scheme to the case of the multipartite GHZ state and quantum gate in virtue of high-order perturbation theory.