Simple construction of Rydberg quantum cloning machines via nonadiabatic geometric quantum operations

Abstract

A theoretical scheme based on the nonadiabatic geometric quantum computation (NGQC) is proposed to realize quantum cloning in the Rydberg atom system. In contrast to previous schemes, the present one utilizes the NGQC to construct the clone machine and thus is more robust against control errors. Meanwhile, to implement the desired cloning framework in the quantum clone machine, the scheme reported by Zhu and Ye [M.-Z. Zhu and L. Ye, Phys. Rev. A 91, 042319 (2015)] based on cavity QED requires a series of single(two)-qubit operations. For the present NGQC-based scheme, through modulating the rotation angle of geometric operations, we can greatly simplify the process of realizing the cloning framework. In addition, through adjusting the relevant parameters, the scheme can perform symmetrical (asymmetrical) universal cloning, optimal symmetrical (asymmetrical) phase-covariant quantum cloning, and optimal symmetrical (asymmetrical) real-state quantum cloning. The present attempt to optimize quantum cloning using geometric quantum control in Rydberg atoms provides a path to robust and simplified quantum cloning, which is meaningful for experiments and has implications for quantum cloning in other quantum systems as well.