Momentum-Transfer to and Elementary-Excitations of a Bose-Einstein Condensate by a Time-Dependent Optical Potential

Abstract

We present results of calculations on Bose-Einstein condensed ${}^{87}$Rb atoms subjected to a moving standing-wave light-potential of the form $V_L(z,t)=V_0(t)\cos (qz-\omega t)$. We calculate the mean-field dynamics (the order paramter) of the condensate and determine the resulting condensate momentum in the $z$ direction, $P_z(q,\omega ,V_0,t_p)$, where $V_0$ is the peak optical potential strength and $t_p$ is the pulse duration. Although the local density approximation for the Bogoliubov excitation spectral distribution is a good approximation for very low optical intensities, long pulse duration and sufficiently large values of the wavevector $q$ of the light-potential, for small $q$, short duration pulses, or for not-so-low intensities, the local density perturbative description of the excitation spectrum breaks down badly, as shown by our results.

8 pages, 7 figures

References in corpus (5)

• Josephson Junction Arrays with Bose-Einstein Condensates
• The Excitation Spectrum of a Bose-Einstein Condensate
• Experimental observation of the Bogoliubov transformation for a Bose-Einstein condensed gas
• Direct observation of the phonon energy in a Bose-Einstein condensate by tomographic imaging
• Bose-Einstein Condensates in Time-Dependent Light Potentials: Adiabatic and Nonadiabatic Behavior of Nonlinear Wave Equations

Cited by in corpus (2)

• Bogoliubov spectrum and Bragg spectroscopy of elongated Bose-Einstein condensates
• Formation of vortices in a dense Bose-Einstein condensate