Characterization of a measurement-based noiseless linear amplifier and its applications
Date
2017
Authors
Zhao, Jie
Haw, Jing-Yan
Symul, Thomas
Lam, Ping
Assad, Syed
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
A noiseless linear amplifier (NLA) adds no noise to the signals it processes, which works only in a probabilistic way. It can be realized approximately with either a physical implementation that truncates the working space of the NLA on a photon-number basis or a measurement-based implementation that realizes the truncation virtually by a bounded postselection filter. To examine the relationship between these two approximate NLAs, we characterize in detail the measurement-based NLA and compare it with its physical counterpart in terms of their abilities to preserve the state Gaussianity and their probability of success. The link between these amplifiers is further clarified by integrating them into a measure-and-prepare setup. We stress the equivalence between the physical and the measurement-based approaches holds only when the effective parameters, the amplification gain, the cutoff, and the amplitude of the input state, are taken into account. Finally, we construct a 1-to-infinity cloner using the two amplifiers and show that a fidelity surpassing the no-cloning limit is achievable with the measurement-based NLA.
Description
Keywords
Citation
Collections
Source
Physical Review A - Atomic, Molecular, and Optical Physics
Type
Journal article