Nonlinear excitations in a compressible quantum Heisenberg chain

[摘要] We investigate, both analytically and numerically, nonlinearly coupled magnetic and elastic excitations of compressible Heisenberg chains. From a shallow water wave treatment of perturbation terms, one can derive two types of coupled equations which are coupled Boussinesq and nonlinear Schrodinger (NLS) equations and coupled Boussinesq and NLS-like equations. We also simulate collisions between magnetic and elastic solitons in the compressible Heisenberg chain when a nonlinearized approach is performed to deal with the magnetic modes in the presence of harmonic as well as anharmonic interactions. Finally, from a fast Fourier transform (FFT) algorithm, the dynamical structure factor is computed for all the numerical solutions of the elastic mode for the model under consideration. (C) 2000 Published by Elsevier Science B.V.

[发布日期] 2000-12-15

[关键词] nonlinear excitations;Heisenberg chain;fast Fourier transform;nonlinear Schrodinger equation