BOSE-GAS WITH NONTRIVIAL PARTICLE INTERACTION AND SEMICLASSICAL INTERPRETATION OF EXOTIC SOLITONS

Many-particle bound states in a Bose gas with a complex pair interacti on between particles are considered. It is shown that the combination of attraction and repulsion between particles leads to the emergence o f bound states with peculiar physical properties. In the limit of a la rge number of bound states in the Hartree approximation, these states are close in the structure and properties to exotic solitons (compacto ns and peakons) in classical systems with weak spatial dispersion. Exa mples of exotic solitons of various types in magnetically ordered medi a are considered. (C) 1998 American Institute of Physics. [S1063-777X( 98)00607-0].