title: Secure Continuous Variable Teleportation and Einstein-Podolsky-Rosen Steering.
abstract: We investigate the resources needed for secure teleportation of coherent states. We extend continuous variable teleportation to include quantum teleamplification protocols that allow nonunity classical gains and a preamplification or postattenuation of the coherent state. We show that, for arbitrary Gaussian protocols and a significant class of Gaussian resources, two-way steering is required to achieve a teleportation fidelity beyond the no-cloning threshold. This provides an operational connection between Gaussian steerability and secure teleportation. We present practical recipes suggesting that heralded noiseless preamplification may enable high-fidelity heralded teleportation, using minimally entangled yet steerable resources.
authors.affiliation: State Key Laboratory of Mesoscopic Physics, School of Physics, Peking University, Collaborative Innovation Center of Quantum Matter, Beijing 100871 China.|Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne 3122, Australia.
authors.forename: Qiongyi
authors.initials: Q
authors.lastname: He
authors.affiliation: Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne 3122, Australia.
authors.forename: Laura
authors.initials: L
authors.lastname: Rosales-Zárate
authors.affiliation: School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Adesso
authors.affiliation: Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne 3122, Australia.
authors.forename: Margaret D
authors.initials: MD
authors.lastname: Reid