Quantum steering in a global state allows an observer to remotely steer a subsystem into different ensembles by performing different local measurements on the other part. We show that, in general, this property cannot be perfectly cloned by any joint operation between a steered subsystem and a third system. Perfect cloning is viable if and only if the initial state is of zero discord. We also investigate the process of cloning the steered qubit of a Bell state using a universal cloning machine. Einstein-Podolsky-Rosen (EPR) steering, which is a type of quantum correlation existing in the states without a local-hidden-state model, is observed in the two copy subsystems. This contradicts the conclusion of no-cloning of quantum steering (EPR steering) [C. Y. Chiu et al., npj Quantum Inf. 2, 16020 (2016)] based on a mutual information criterion for EPR steering.
@article{arxiv.2204.07322,
title = {Quantum cloning of steering},
author = {Dian Zhu and Wei-Min Shang and Fu-Lin Zhang and Jing-Ling Chen},
journal= {arXiv preprint arXiv:2204.07322},
year = {2023}
}
Comments
Published by CPL as Editors' Suggestion; This work has been reported in Physics World (https://physicsworld.com/a/cloning-quantum-steering-is-a-no-go/)