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R A Sammut

Publications and source records attributed to R A Sammut.

5 recordsLinked to original sources
PubMed2001

Nonlinear dynamics of higher-order solitons near the oscillatory instability threshold.

Nonlinear theory describing the dynamics of solitons in the vicinity of oscillatory instability threshold with a low frequency offset is developed. The theory is tested on the example of parametric degenerate four-wave mixing. All major predictions of our theory are in agreement with the results of direct numerical modeling. This includes the position of oscillatory instability threshold, instability rates, and various instability development scenarios.

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PubMed2001

Interaction of two one-dimensional Bose-Einstein solitons: chaos and energy exchange.

We analyze the bright soliton interactions of a Bose-Einstein condensate in quasi-one-dimensional traps putting an emphasis on integrability break down due to a trapping potential. In particular, we derive a simple analytical model, which describes well all major features of soliton dynamics including chaos and energy exchange between interacting solitons induced by the trapping potential.

Journal Article↗
PubMed2001

Stable localized vortex solitons.

We demonstrate that parametric interaction of a fundamental beam with its second harmonic in bulk media, in the presence of self-defocusing third-order nonlinearity, gives rise to the first ever examples of completely stable localized ring-shaped solitons with intrinsic vorticity n=1 and n=2. The stability is demonstrated both in direct simulations and by computing eigenvalues of the corresponding linearized equations. A potential application of the (2+1)-dimensional ring solitons in optics is a possibility to design a reconfigurable multichannel system guiding signal beams.

Journal Article↗