%0 Journal Article %1 Usuga2010Noisepowered %A Usuga, Mario A. %A Muller, Christian R. %A Wittmann, Christoffer %A Marek, Petr %A Filip, Radim %A Marquardt, Christoph %A Leuchs, Gerd %A Andersen, Ulrik L. %D 2010 %I Nature Publishing Group %J Nature Physics %K optical, quantum-information %N 10 %P 767--771 %R 10.1038/nphys1743 %T Noise-powered probabilistic concentration of phase information %U http://dx.doi.org/10.1038/nphys1743 %V 6 %X Phase-insensitive optical amplification of an unknown quantum state is known to be a fundamentally noisy operation that inevitably adds noise to the amplified state1, 2, 3, 4, 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, 7, 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 scheme9. 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.

@article{Usuga2010Noisepowered, abstract = {{Phase-insensitive optical amplification of an unknown quantum state is known to be a fundamentally noisy operation that inevitably adds noise to the amplified state1, 2, 3, 4, 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, 7, 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 scheme9. 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.}}, added-at = {2019-02-26T15:22:34.000+0100}, author = {Usuga, Mario A. and Muller, Christian R. and Wittmann, Christoffer and Marek, Petr and Filip, Radim and Marquardt, Christoph and Leuchs, Gerd and Andersen, Ulrik L.}, biburl = {https://www.bibsonomy.org/bibtex/2baebe2d3c3e59bba1f8372ee99103e9d/rspreeuw}, citeulike-article-id = {7944478}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/nphys1743}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/nphys1743}, day = 15, doi = {10.1038/nphys1743}, interhash = {16fbd729d40e45454752871780080a06}, intrahash = {baebe2d3c3e59bba1f8372ee99103e9d}, issn = {1745-2473}, journal = {Nature Physics}, keywords = {optical, quantum-information}, month = aug, number = 10, pages = {767--771}, posted-at = {2010-10-04 10:26:33}, priority = {2}, publisher = {Nature Publishing Group}, timestamp = {2019-02-26T15:22:34.000+0100}, title = {{Noise-powered probabilistic concentration of phase information}}, url = {http://dx.doi.org/10.1038/nphys1743}, volume = 6, year = 2010 }