arXiv:quant-ph/0301122 · Physical Review A
Propagation and breathing of matter–wave-packet trains
Wenhua Hai, Chaohong Lee, Guishu Chong
Abstract
We find a set of different orthonormalized states of a nonstationary harmonic oscillator and use them to expand the solution of the Gross-Pitaevskii equation with harmonic potential. The expansion series describes wave-packet trains of a Bose-Einstein condensate, which may be induced initially by the modulational instability. The center of any wave-packet train oscillates like a classical harmonic oscillator of frequency $\ensuremath{\omega}$. The width and height of the wave packet and the distance between two wave packets change simultaneously like an array of breathers with frequency $2\ensuremath{\omega}$. We demonstrate analytically and numerically that for a set of suitable parameters the wave-packet trains can be more exactly fitted to the matter-wave soliton trains observed by Strecker et al. and reported in Nature (London) 417, 150 (2002).