Superfluid dynamics of a Bose-Einstein condensate in a periodic potential
Year: 2003
Authors: Menotti C., Smerzi A., Trombettoni A.
Autors Affiliation: Univ Trent, Ist Nazl Fis Mat, BEC CRS, I-38050 Povo, Italy; Univ Trent, Dipartimento Fis, I-38050 Povo, Italy; Univ Cattolica Sacro Cuore, Dipartimento Matemat & Fis, I-25121 Brescia, Italy; Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA; Univ Parma, Ist Nazl Fis Mat, I-43100 Parma, Italy; Univ Parma, Dipartimento Fis, I-43100 Parma, Italy.
Abstract: We investigate the superfluid properties of a Bose-Einstein condensate (BEC) trapped in a one-dimensional periodic potential. We study, both analytically (in the tight binding limit) and numerically, the Bloch chemical potential, the Bloch energy and the Bogoliubov dispersion relation, and we introduce two different, density dependent, effective masses and group velocities. The Bogoliubov spectrum predicts the existence of sound waves, and the arising of energetic and dynamical instabilities at critical values of the BEC quasi-momentum which dramatically affect its coherence properties. We investigate the dependence of the dipole and Bloch oscillation frequencies in terms of an effective mass averaged over the density of the condensate. We illustrate our results with several animations obtained solving numerically the time-dependent Gross-Pitaevskii equation.
Journal/Review: NEW JOURNAL OF PHYSICS
Volume: 5 Pages from: 112-1 to: 112-20
KeyWords: Optical Lattices; Tunnel Arrays; Instabilities; Transition; Insulator; AtomsDOI: 10.1088/1367-2630/5/1/112Citations: 84data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-20References taken from IsiWeb of Knowledge: (subscribers only)