%0 Journal Article %1 Appel2009Mesoscopic %A Appel, J. %A Windpassinger, P. J. %A Oblak, D. %A Hoff, U. B. %A Kjærgaard, N. %A Polzik, E. S. %D 2009 %J Proceedings of the National Academy of Sciences %K entanglement, spin-squeezing %N 27 %P 10960--10965 %R 10.1073/pnas.0901550106 %T Mesoscopic atomic entanglement for precision measurements beyond the standard quantum limit %U http://dx.doi.org/10.1073/pnas.0901550106 %V 106 %X Squeezing of quantum fluctuations by means of entanglement is a well-recognized goal in the field of quantum information science and precision measurements. In particular, squeezing the fluctuations via entanglement between 2-level atoms can improve the precision of sensing, clocks, metrology, and spectroscopy. Here, we demonstrate 3.4 dB of metrologically relevant squeezing and entanglement for ≳ 105 cold caesium atoms via a quantum nondemolition (QND) measurement on the atom clock levels. We show that there is an optimal degree of decoherence induced by the quantum measurement which maximizes the generated entanglement. A 2-color QND scheme used in this paper is shown to have a number of advantages for entanglement generation as compared with a single-color QND measurement.

@article{Appel2009Mesoscopic, abstract = {{Squeezing of quantum fluctuations by means of entanglement is a well-recognized goal in the field of quantum information science and precision measurements. In particular, squeezing the fluctuations via entanglement between 2-level atoms can improve the precision of sensing, clocks, metrology, and spectroscopy. Here, we demonstrate 3.4 dB of metrologically relevant squeezing and entanglement for ≳ 105 cold caesium atoms via a quantum nondemolition (QND) measurement on the atom clock levels. We show that there is an optimal degree of decoherence induced by the quantum measurement which maximizes the generated entanglement. A 2-color QND scheme used in this paper is shown to have a number of advantages for entanglement generation as compared with a single-color QND measurement.}}, added-at = {2019-02-26T15:22:34.000+0100}, author = {Appel, J. and Windpassinger, P. J. and Oblak, D. and Hoff, U. B. and Kj{\ae}rgaard, N. and Polzik, E. S.}, biburl = {https://www.bibsonomy.org/bibtex/27155a0f299558ef0e37150baa8e16f25/rspreeuw}, citeulike-article-id = {6109312}, citeulike-linkout-0 = {http://dx.doi.org/10.1073/pnas.0901550106}, citeulike-linkout-1 = {http://www.pnas.org/content/106/27/10960.abstract}, citeulike-linkout-2 = {http://www.pnas.org/content/106/27/10960.full.pdf}, citeulike-linkout-3 = {http://www.pnas.org/cgi/content/abstract/106/27/10960}, citeulike-linkout-4 = {http://view.ncbi.nlm.nih.gov/pubmed/19541646}, citeulike-linkout-5 = {http://www.hubmed.org/display.cgi?uids=19541646}, day = 7, doi = {10.1073/pnas.0901550106}, interhash = {5800aed664ebc0342ccce6a4ad057ff5}, intrahash = {7155a0f299558ef0e37150baa8e16f25}, journal = {Proceedings of the National Academy of Sciences}, keywords = {entanglement, spin-squeezing}, month = jul, number = 27, pages = {10960--10965}, pmid = {19541646}, posted-at = {2009-11-13 13:23:37}, priority = {2}, timestamp = {2019-02-26T15:22:34.000+0100}, title = {{Mesoscopic atomic entanglement for precision measurements beyond the standard quantum limit}}, url = {http://dx.doi.org/10.1073/pnas.0901550106}, volume = 106, year = 2009 }