Nir Davidson

We report the observation of the opto-mechanical strain applied to ultra-cold rubidium atoms when shined on by an intense, far detuned homogenous laser beam. This force acts perpendicular to the laser beams direction and depends on the atomic cloud density profile, effectively generating interactions between the atoms. We refer to this force as electrostriction, since it resembles shape changes of materials under the application of a static electric field. We experimentally demonstrate the basic features of electrostriction, distinguishing it from the well-established scattering and dipole forces, and proving it is a new type of force [1]. We also report on experimental study the anomalous real-space and phase-space dynamics of ultra-cold atoms in a one dimension where the spatial distribution exhibits fractional self-similarity and Lévy statistics [2]. We show that the position-velocity correlation function builds up on a timescale related to the initial conditions of the ensemble and then decays asymptotically as a power-law, following a simple scaling theory involving the power-law asymptotic dynamics of position and velocity [3]. Finally, for trapped atoms we demonstrate a breakdown of equipartition theorem [4] predicted for anomalous dynamics in [5]. 1. N. Matzliah, H. Edri, A. Sinay, R. Ozeri, and N. Davidson, Phys. Rev. Lett. 119, 163201 (2017). 2. Y. Sagi, M. Brook, I. Almog, and N. Davidson, Phys. Rev. Lett. 108, 093002 (2012). 3. G. Afek, J. Coslovsky, A. Courvoisier, O. Livneh, and N. Davidson, Phys. Rev. Lett. 119, 060602 (2017). 4. G. Afek, A. Courvoisier, A. Cheplev, and N. Davidson, submitted. 5. Dechant, D. Kessler, and E. Barkai, Phys. Rev. Lett. 115, 173006 (2015).