Momentum transfer to and elementary excitations of a BoseEinstein condensate by a timedependent optical potential
Abstract
We present results of calculations on BoseEinsteincondensed ^{87}Rb atoms subjected to a moving standingwave light potential of the form V_{L}(z,t)=V_{0}(t)cos(qzωt). We calculate the meanfield dynamics (the order parameter) of the condensate and determine the resulting condensate momentum in the z direction, P_{z}(q,ω,V_{0},t_{p}), where V_{0} is the peak optical potential strength and t_{p} is the pulse duration. Although the localdensity 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 wave vector q of the light potential, for small q, short duration pulses, or for notsolow intensities, the localdensity perturbative description of the excitation spectrum breaks down badly, as shown by our results.
 Publication:

Physical Review A
 Pub Date:
 October 2002
 DOI:
 10.1103/PhysRevA.66.043614
 arXiv:
 arXiv:condmat/0207749
 Bibcode:
 2002PhRvA..66d3614B
 Keywords:

 03.75.Fi;
 67.90.+z;
 71.35.Lk;
 Other topics in quantum fluids and solids;
 liquid and solid helium;
 Collective effects;
 Condensed Matter  Soft Condensed Matter;
 Condensed Matter  Statistical Mechanics
 EPrint:
 8 pages, 7 figures