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Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Measurement-based noiseless linear amplification for quantum communication

Helen M. Chrzanowski, Nathan Walk, Jing Yan Haw, Oliver Thearle, Syed M. Assad, Jiří Janoušek, Sajedi Hosseini, Timothy C. Ralph, Thomas Symul, Ping Koy Lam

Published Nov 18, 2014• 43 citations

Abstract

Entanglement distillation is an indispensable ingredient in extended quantum communication networks. Distillation protocols are necessarily non-deterministic and require non-trivial experimental techniques such as noiseless amplification. We show that noiseless amplification could be achieved by performing a post-selective filtering of measurement outcomes. We termed this protocol measurement-based noiseless linear amplification (MBNLA). We apply this protocol to entanglement that suffers transmission loss of up to the equivalent of 100km of optical fibre and show that it is capable of distilling entanglement to a level stronger than that achievable by transmitting a maximally entangled state through the same channel. We also provide a proof-of-principle demonstration of secret key extraction from an otherwise insecure regime via MBNLA. Compared to its physical counterpart, MBNLA not only is easier in term of implementation, but also allows one to achieve near optimal probability of success.

DOI: 10.1117/12.2071884

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