Action Of Variable Field Research Articles

Nonlinear resonances and dynamical chaos of solitons in the three-dimensional sine-Gordon system under the action of a parametric variable field

The dynamics of spherically symmetric magnetic kinks in a variable field has been studied. The problem is described by the three-dimensional sine-Gordon equation with a parametrically acting variable field. The conditions of existence of nonlinear resonances of kink oscillations under the action of the variable field as well as the conditions of appearance of dynamical stochasticity in a kink motion have been found.

Emission from, quasi-classical quantization, and stochastic decay of sine-Gordon solitons in external fields

Different dynamical problems for solitons (kinks and breathers) of a sine-Gordon equation perturbed by small Hamiltonian terms describing constant and variable (time-periodic or randomly varying) external fields in various physical problems, e.g. external magnetic field in weak ferromagnets and bias current in long Josephson junctions, are considered. Among these problems are energy emission generated by a soliton in variable spatially homogeneous fields (both the resonant and nonresonant cases being considered) or in constant field of an attractive micro-inhomogeneity (a magnetic impurity in a ferromagnet or a micro-resistance in a Josephson junction); perturbation-induced corrections to the quasi-classical spectrum of a quantized small-amplitude breather; stochastic decay of a weakly bound breather into a kink-antikink pair under the action of variable field or in the field of a microinhomogeneity. The influence of dissipation on the considered effects is analyzed too.