Parametric Resonance Phenomena in Bose-Einstein Condensates: Enhanced Quantum Tunneling of Coherent Matter Pulses
Abstract
Description
We investigate the quantum tunneling of a Bose-Einstein condensate confined in a optical trap. We show that periodic pulses of coherent matter are emitted from the trap by using an oscillating energy barrier. Moreover, the emitted fraction of condensed atoms strongly increases if the period of oscillation of the height of the energy barrier is in parametric resonance with the period of oscillation of the center of mass of the condensate inside the potential well. Our model is analyzed by numerically solving the nonpolynomial Schrodinger equation (NPSE), an effective one-dimensional equation which describes the macroscopic wavefunction of Bose condensates under transverse harmonic confinement. The range of validity of NPSE is discussed and compared with that of Gross-Pitaevskii equation.
11 pages, 2 figures, presented to the 'Laser Physics Workshop 2002', seminar on 'Bose-Einstein Condensation of Trapped Atoms', Bratislava, July 2002, to be published in Laser Physics; related papers can be found at http://www.mi.infm.it/salasnich/tdqg.html
11 pages, 2 figures, presented to the 'Laser Physics Workshop 2002', seminar on 'Bose-Einstein Condensation of Trapped Atoms', Bratislava, July 2002, to be published in Laser Physics; related papers can be found at http://www.mi.infm.it/salasnich/tdqg.html