Bar-Gill, N., Rowen, E., Kurizki, G. & Davidson, N. Short-time enhancement of the decay of coherent excitations in Bose-Einstein Condensates. Physical review letters 102, (2009).Abstract
We study, both experimentally and theoretically, short-time modifications of the decay of excitations in a {Bose-Einstein} Condensate {(BEC)} embedded in an optical lattice. Strong enhancement of the decay is observed compared to the Golden Rule results. This enhancement of decay increases with the lattice depth. It indicates that the description of decay modifications of few-body quantum systems also holds for decay of many-body excitations of a {BEC.}
Rowen, E., Bar-Gill, N., Pugatch, R. & Davidson, N. Energy-dependent damping of excitations over an elongated Bose-Einstein condensate. Physical Review A 77, (2008).
Rowen, E., Bar-Gill, N. & Davidson, N. Quantum enhancement of higher-order phononlike excitations of a Bose-Einstein condensate. Physical review letters 101, (2008).Abstract
In a {Bose-Einstein} condensate, the excitation of a Bogoliubov phonon with low momentum (e.g., by a two-photon Bragg process) is strongly suppressed due to destructive interference between two indistinguishable excitation pathways. Here we show that scattering of this sound excitation into a double-momentum mode is strongly enhanced due to constructive interference. This enhancement yields an inherent amplification of second-order sound excitations of the condensate, as we confirm experimentally. We further show that due to parity considerations, this effect is extended to higher-order excitations.
Bar-Gill, N., Rowen, E.E. & Davidson, N. Spectroscopy of strong-pulse superradiance in a Bose-Einstein condensate. Physical Review A 76, 4, 043603 (2007).
Kolář, M., Opatrný, T., Bar-Gill, N., Erez, N. & Kurizki, G. Path–phase duality with intraparticle translational–internal entanglement. New Journal of Physics 9, (2007). Publisher's Version
Kolár, M., tomás Opatrný,, Bar-Gill, N. & Kurizki, G. Betting on interferometric paths and phases using translational-internal entanglement: the greedy king game. International Journal of Modern Physics B 20, (2006). Publisher's Version
Kurizki, G., Bar-Gill, N., Clausen, J., Kolář, M. & Opatrný, T. Cheating on Complementarity and Interference by Translational – Internal Entanglement. Quantum Information Processing 5, (2006). Publisher's Version
Bar-Gill, N. & Kurizki, G. Signatures of strong momentum localization via entanglement of translational and internal states. Physical review letters 97, (2006).Abstract
We show that atoms or molecules subject to fields that couple their internal and translational (momentum) states may undergo a crossover from randomization (diffusion) to strong localization (sharpening) of their momentum distribution. The predicted crossover should be manifest by a drastic change of the interference pattern as a function of the coupling fields.
Bar-Gill, N., Botton, M. & Ron, A. Dynamics of a Lasing Atom in Hot Plasma. Eur. Phys. J. D 30, 3, 317 (2004).