Robust Gaussian Teleportation with Attenuations and Non-unity Gain

Abstract

The average fidelity of the teleportation of a coherent state is calculated for general Gaussian bipartite systems shared by the partners of the protocol, Alice and Bob. It is considered that the shared Gaussian bipartite modes suffer independent attenuations before the processing of Alice and Bob. Moreover the classical communication between the partners can be controlled by a gain not necessarily unitary. Comparing with the classical fidelity threshold of measure-and-prepare methods, we establish several genuinely quantum teleportation conditions which depend on the gain and the local attenuations. Considering that the gain can be tuned to maximize the bipartite state set able to genuinely quantum teleportation, a condition for teleportation robust to local attenuations is found. This condition is demonstrated to be essentially equivalent to the condition of robust Gaussian bipartite entanglement, obtained in previous articles, showing that the attenuation robustness is an entanglement property relevant for characterization and application of bipartite systems. For the derivation of the robust teleportation conditions, the Gaussian operations onto the bipartite system are thoroughly studied, so that the transformations that maintain the fidelity invariant are found. Some scenarios for different Gaussian bipartite states are presented and discussed.

25 pages, 4 figures. To be submitted for publication

References in corpus (10)

• Quantum teleportation using active feed-forward between two Canary Islands
• Quantum teleportation and entanglement distribution over 100-kilometre free-space channels
• Quantum Teleportation with Continuous Variables: a survey
• Equivalence between Entanglement and the Optimal Fidelity of Continuous Variable Teleportation
• Experimental demonstration of quantum teleportation of broadband squeezing
• Robustness of bipartite Gaussian entangled beams propagating in lossy channels
• Quantum optics experiments to the International Space Station ISS: a proposal
• Experimental analysis of decoherence of quantumness in a continuous variables bi-partite entangled system
• Fidelity criterion for quantum-domain transmission and storage of coherent states beyond unit-gain constraint
• Simple proof of the quantum benchmark fidelity for continuous-variable quantum devices