Mikhail Bogdan, Leading Researcher.

E-mail: bogdan@ilt.kharkov.ua

Graduated from Kharkov State University in 1974. 
PhD Phys & Math, ILTPE, 1984. 
DSc Phys & Math , ILTPE, 2002.

Was born in Savintsy, Kharkov Region, Ukraine. Has been working at ILTPE as a junior researcher from 1978 to 1986, as a researcher from 1986 to 1991, then as a senior researcher from 1991 to 2004. 

Research area: 
the theory of nonlinear phenomena in condensed matter physics based on the soliton concept and its applications for description of nonlinear effects in solids. Main results are finding of exact multisoliton solutions of the Landau-Lifshitz equation for one-dimensional biaxial ferromagnet, discovery of the oscillatory instability in soliton dynamics, finding the exact discrete multibreather solutions in nonlinear lattices.

Last five years activity and current interests:

Subjects of current investigations include dynamical properties of nonlinear excitations in condensed matter, specially stability properties, computer simulation of the nonlinear dynamics, nonlinear resonant phenomena in condensed matter, regular and chaotic soliton dynamics in microwave fields, theoretical description of experimental data of the nonlinear resonance in low-dimensional magnets by the use of nonlinear analysis of signal time series, magnetic vortices and frustration phenomena in two-dimensional magnets, soliton interaction, formation of multisoliton complexes and discrete multibreather excitations and their coherent motion in strongly dispersive media.

Theory of nonlinear phenomena in magnets:

(i) a complete theoretical description of experimental data of chaotic regimes of the microwave energy absorption in a quasi-two-dimensional metal-organic antiferromagnet was carried out by the nonlinear analysis method of time series. As a result the systematic investigation of chaos in the relaxation oscillations of the microwave field absorption was done for the first time and the transition to chaos through the irregular periods in spin dynamics of the antiferromagnet was described quantitatively.
(ii) the magnetic vortex-impurity interaction in the layered magnets was investigated and the vortex-antivortex patterns in antiferromagnets with nonmagnetic and magnetic impurities were found.

Theory of multisoliton complexes in strongly dispersive systems:

The concept of bound multisoliton complexes in the dispersive media was developed. The mechanism of formation of complexes was found and their properties and conditions of radiationless dynamics were specified. The nature and mechanism of formation of the bound soliton state in nonlinear systems with paramentric pumping and dissipation were revealed.

Theory of discrete breathers dynamics in nonlinear lattices:

The exact discrete multibreather solution for integrable one-dimensional nonlinear lattice transmission line equations were found for the first time. Discrete multibreather interactions and dynamical characteristics of the scattering process were explicitly described.

Selected publication:

1. M.M.Bogdan, A.M.Kosevich, G.A.Maugin. Soliton Complex Dynamics in Strongly Dispersive Medium. Wave Motion. V.34, 1-26 (2001).