Journal article ยท Preprint article
Noise-powered probabilistic concentration of phase information
Phase-insensitive optical amplification of an unknown quantum state is known to be a fundamentally noisy operation that inevitably adds noise to the amplified state(1-5). However, this fundamental noise penalty in amplification can be circumvented by resorting to a probabilistic scheme as recently proposed and demonstrated in refs 6-8.
These amplifiers are based on highly non-classical resources in a complex interferometer. Here we demonstrate a probabilistic quantum amplifier beating the fundamental quantum limit using a thermal-noise source and a photon-number-subtraction scheme(9). The experiment shows, surprisingly, that the addition of incoherent noise leads to a noiselessly amplified output state with a phase uncertainty below the uncertainty of the state before amplification.
This amplifier might become a valuable quantum tool in future quantum metrological schemes and quantum communication protocols.
Language: | English |
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Publisher: | Nature Publishing Group UK |
Year: | 2010 |
Pages: | 767-771 |
ISSN: | 17452473 and 17452481 |
Types: | Journal article and Preprint article |
DOI: | 10.1038/NPHYS1743 |
ORCIDs: | Andersen, Ulrik Lund |