Publications by the Laboratory of Theoretical Physics

Modulational instability of matter waves under strong nonlinearity management, F. Kh. Abdullaev, A. A. Abdumalikov, R.M. Galimzyanov, Physica D 238, 1345 (2009).      [PDF-file (1 MB)] Abstract: We study modulational instability of matter-waves in BoseEinstein condensates (BEC) under strong temporal nonlinearity-management. Both BEC in an optical lattice and homogeneous BEC are considered in the framework of the GrossPitaevskii equation, averaged over rapid time modulations. For a BEC in an optical lattice, it is shown that the loop formed on a dispersion curve undergoes transformation due to the nonlinearity-management. A critical strength for the nonlinearity-management strength is obtained that changes the character of instability of an attractive condensate. MI is shown to occur below (above) the threshold for the positive (negative) effective mass. The enhancement of number of atoms in the nonlinearity-managed gap soliton is revealed. The papers have Copyright © by the corresponding publishers. The papers may be downloaded for personal use only. Any other use requires prior permission of the author and the publisher.