Hamburg 2009 – wissenschaftliches Programm

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SYLV: Symposium Lokalisierung und Verschränkung in photoinduzierten Prozessen

SYLV 1: SYLV I

SYLV 1.4: Hauptvortrag

Montag, 2. März 2009, 15:30–16:00, VMP 8 HS

Entanglement-assisted Ramsey Spectroscopy with Atomic Ensembles — •Eugene Polzik — The Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, Copenhagen, Denmark

Ultimate quantum fluctuations which limit the fundamental precision in metrology can be only reduced by entanglement of particles. In particular, squeezing of the fluctuations called the spin projection noise by means of generation of entanglement in an ensemble of atoms can improve the precision of Ramsey spectroscopy and of atomic clocks. A powerful tool for generation of multiparticle entanglement is a quantum nondemolition measurement (QND). We will describe the fundamentals of QND measurement of atomic collective state with light and present a recent experiment [1] where this method has been used to reduce the projection noise on the clock transition in an ensemble of 105 cold and trapped Cesium atoms. Nondestructive probing can be also used to monitor classical properties and dynamics of atoms with excellent S/N ratio [2].

[1] J. Appel, P. J. Windpassinger, D. Oblak, U. B. Hoff, N. Kjærgaard, and E. S. Polzik. Quantum noise squeezing and entanglement on the atomic clock transition. Submitted for publication. arXiv:0810.3545

[2] Windpassinger, P. J., Oblak, D., Petrov, P. G., Kubasik, M., Saffman, M., Alzar, C. L. Garrido, Appel, J., Mueller, J. H., Kjærgaard, N., and Polzik, E. S. Nondestructive probing of Rabi oscillations on the cesium clock transition near the standard quantum limit. Phys. Rev. Lett., 100, 103601 (2008); Windpassinger, P. J., Oblak, D., Hoff, U.B., Appel, J., Kjærgaard, N., and Polzik, E. S., Inhomogeneous light shift effects on atomic quantum state evolution in non-destructive measurements. New J. of Physics, 10, 053032 (2008).