Department of theoretical physics

Founded in 1944. The department has 22 employees, including 5 PhDs/doctors of sciences and 9 PhDs/candidates of sciences.

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Physics of low-dimensional systems:

  • interaction of electromagnetic radiation with matter; optical emission, optoacoustic properties, electron-lattice energy exchange in small metal particles, island films, and metallic particles in dielectric matrices;
  • theory of intermolecular chains with hydrogen bonds: proton transport along molecular chains; effects of multi-particle tunneling and transport in molecular chains;
  • macroscopic quantum tunneling in a system of hydrogen sublattices;
  • adatoms and surface systems: diffusion in ordered adatom structures on a crystalline surface;
  • diffusion under the conditions of first-order phase transitions, tracer diffusion;
  • kinetic processes, statistical description of systems with interaction, pattern formation in condensed matter;
  • nanoelectronics;
  • electromagnetic phenomena in electrical and optical metamaterials, techniques of calculating the effective parameters of metamaterials for different geometries and applications.

Liquid crystals theory: pattern formation, mixtures and suspensions.

Quantum optics:

  • cavity QED;
  • quantum measurement theory;
  • nonclassical properties of quantum states;
  • theory of quantum light in the turbulent atmosphere.

Nonlinear theory of oscillations and waves.

Mathematical modeling in the physics of mechanoreceptors.

Nonlinear mathematical models and methods of solution of nonlinear and ill-posed problems in laser physics.

Main achievements in recent years

  • theory of absorption and emission by small metal particles and their assemblages (island films); peculiarities of electron-lattice energy exchange in metal nanoparticles;
  • theory of diffusion in a system of strongly interacting adatoms: mass transfer due to migration of defects in ordered adatom structures, migration at undercritical temperatures in the 2D lattice-gas system accompanied by droplet ripening;
  • theoretical description of dissipative Williams domains in a two-frequency electric field;
  • inclusion of the divergent K13 term in the elasticity theory of spatially oriented liquid crystals;
  • theory of the effective interaction of micro- and macrodopands in a nematic medium;
  • theory of spatially inhomogeneous many-particle systems;
  • theory of high-Q cavities with unwanted absorption and scattering;
  • theory of the propagation of quantum light through a turbulent atmosphere;
  • the effect of fake violation of quantum-bound Bell parameter;
  • theory of quantum-light detection in the presence of dark counts and background radiation;
  • theory of the transition to multiphoton relaxation of interacting atoms and the amplification of the superradiance effect;
  • mathematical model of a gravisensing system;
  • new wave solutions to the canonical model of hydrodynamics;
  • new technique for the construction of nonlinear evolution equations, generalization of high-order nonlinear Schrodinger equations;
  • mathematical models of multiple-beam laser models.

Most important achievements in the department history

  • 1944–1950. Theory of polarons (Pekar S.I.);
  • 1945–1953. Foundations of the theory of excitons in molecular crystals (Davydov O.S.);
  • 1960–1975. Theory of kinetic and fluctuation processes in nonequilibrium electron-phonon systems for semiconductors with different band structures and with the prevailing role of electron-electron (hole-hole) interactions. Kinetic coefficients, fluctuation characteristics, and cross-sections of wave scattering by fluctuations were investigated depending on carrier heating degree and band structure peculiarities for typical semiconductors. Theory for anisotropic and nonparabolic semiconductor structures (Tomchuk P.M., Chumak O.O., Shenderovskyi V.A., partially with Dykman I.M. [Institute of Semiconductors]);
  • 1967–1977. Theory of the pinch effect in a semiconductor plasma and the oscillistor theory on the basis of multivalley semiconductors (Vladimirov V.V., Gorshkov V.M., Schedrin A.I.).
  • 1969–1970. Theory of intrinsic defect mechanism of conduction and conduction self-compensation in ion semiconductors (Vinetskyi V.L.).
  • 1972–1977. Kinetic theory of laser generation in spectrally inhomogeneous solid bodies (Mashkevich V.S., Godenko L.P.).
  • 1976–1979. Band model of the recording of dynamic holograms in photorefractive crystals, which provided a basis for the majority of studies in dynamic holography (Vinetskyi V.L., Kukhtarev N.V.).
  • 1978–1981. Theoretical prediction and experimental confirmation of the existence of magnetostatic solitons in ferromagnetic films and magnetoacoustic solitons in ferro- and antiferromagnetics (Lukomsky V.P.).
  • 1982–1985. Theory of superlattices that are formed by hot electrons in a semiconductor in the field of coherent light beams. Theory of light diffraction on such superlattices. Theory of nonlinear propagation of infrared radiation in multivalley semiconductors under the conditions of superlattice formation (Tomchuk P.M., Chumak O.O., partially with Dykman I.M. [Institute of Semiconductors]).
  • 1976–1981. Theory of injection-stimulated conversion of defects in light-emitting semiconductor structures (Lev B.I., Tomchuk P.M.).
  • 1973–1980. A new method for describing the nonequilibrium fluctuations in a superconductor plasma that was used to construct the theory of electric noise in systems which cannot be described by the Boltzmann equation (quantum frequency range, quantizing electric or magnetic fields, strong interaction of carriers with resonance dopants) (Tomchuk P.M., Chumak O.O., Rozhkov S.S.).
  • 1966–1968, 1985–1989. Concept of hot electrons in metallic nanoparticles that was used to construct the theory of nonlinear current-voltage characteristics and the theory of electron and photon emission from metallic island films under the current-induced or laser-induced heating of electrons (Tomchuk P.M.).
  • 1980–1990. Theory of transport phenomena in low-symmetry and narrow-band semiconductors (Shenderovskyi V.A.).
  • 1998–2003. Theory of diffusion in adsorptive systems with strong interaction (Chumak O.O.).
  • 1990–1992, 2006–2007. Dimension-dependent theory of surface and volume electron-lattice energy exchange in metallic nanoparticles (Bilotsky Ye.D., Tomchuk P.M.).
  • 1984–2003. Theory of proton conduction in molecular chains with hydrogen bonds in which proton polarons serve as charge carriers. Theory of the coherent tunelling polarization in such chains (Krasnoholvets V.V., Lukyanets S.P., Tomchuk P.M.).
  • 1990–2009. Revealing the optical bistability phenomenon in crystals with diffusion nonlinearity by the methods of computational physics. New mathematical models of the measurement tracts of experimental laser devices and new models of nonstationary multiple-beam interactions (Starkov V.M.).
  • 1999–2003. Theory of permolecular structures in liquid crystals with macroclusters. Description of the known structures and prediction of some new structures induced by macro- and microdopants or boundary conditions in liquid crystals. (Lev B.I., Pergamenshchik V.M., Chernyshuk S.B.).
  • 2001–2004. New wave solutions to the canonical model of hydrodynamics (Gandzha I.S., Lukomsky V.P.);
  • 1986–1995, 2005–2008. A new method of the reduction of nonlinear evolution equations (Lukomsky V.P., during the last period together with Gandzha I.S.).
  • 2001–2004. A new equation for describing the modulations of gravity waves on a fluid surface (high-order nonlinear Schrodinger equation) (Sedletsky Yu.V.).
  • 1997–2011. Investigation of the dependence of optical properties of metallic nanoparticles on their shape. Revealing an abnormally high sensitivity of absorption in regard to the nanoparticle shape. The energy absorbed by the particles of equal volume but of different shape can differ by several orders of magnitude. Theory of absorption of ultra-short laser pulses by ellipse-like metal nanoparticles. (Tomchuk P.M., Grigorchuk N.I. [Institute for Theoretical Physics]).
  • 2002–2007. A phenomenological theory of high-Q optical and microwave cavities with allowance for absorption and scattering (Semenov A.A., Vasylyev D.Yu., Prof. Vogel W. [Universitaet Rostock, Germany], Prof. Welsch D.-G. and Khanbekyan M. [Friedrich-Schiller Universitaet Jena, Germany]).
  • 2002–2008. Theory of angular dependences of hot electron emission in multivalley semiconductors (Tomchuk P.M.).
  • 1995–2009. Mathematical models of physical processes in biological systems of spatial orientation and gravireception: computer 3D model of the otholite membrane, model of the dynamics of semicircular channels, model of the interaction of receptor cells with the surrounding gel (Kondrachuk A.V.).
  • 2010-2012. Theory of elastic interaction between arbitrary colloidal particles in confined nematic liquid crystals in the presence of an external electric or magnetic fields. (Chernyshuk S.B., Lev B.I. [Institute for Theoretical Physics], Tovkach O.M. [Institute for Theoretical Physics]).
  • 2010–2013. Generalization of the technique of taking into account the dispersive and nonlinear effects in the averaged Lagrangian approach for describing the modulations of gravity waves on the fluid surface (Sedletsky Yu.V.).
  • 2007-2013. Theory of quantum-light propagation through the turbulent atmosphere. It has been theoretically shown that the turbulent atmosphere may preserve nonclassical properties of quantum light much better comparing with glass fibers of the same losses (Chumak O.O., Semenov A.O.).











  • Chalyi A.V., Lukomsky V.P., Gandzha I.S., Tsekhmister Ya.V., Chalyi K.O., Nonlinear Processes in Physics: Oscillations, Waves, Self-Organization, Kyiv, Chetverta Khvylya, ISBN 9665291092 (2004) [in Ukrainian].
  • Khanbekyan M., Knoell L., Semenov A.A., Vogel W., Welsch D.-G., Quantum-state extraction from high-Q cavities, Phys. Rev. A, vol. 69, 043807 (2004)
  • Lukomsky V.P., Gandzha I.S., Cascades of subharmonic stationary states in strongly non-linear driven planar systems, Journal of Sound and Vibration, vol. 275, 351 (2004)
  • Smalyukh I.I., Chernyshuk S., Lev B.I., Nych A.B., Ognysta U., Nazarenko V.G., Lavrentovich O.D., Ordered droplet structures at the liquid crystal surface and elastic-capillary colloidal interactions, Phys. Rev. Lett., vol. 93, 117801 (2004)
  • Tomchuk P.M., Peculiarities of the light absorption and emission by free electrons in multivalley semiconductors, Ukr. J. Phys., vol. 49, 681 (2004)


  • Krasnogolovets V.V., Tomchuk P.M., Lukyanets S.P., Proton transfer and coherent phenomena in molecular structures with hydrogen bonds, Adv. Chem. Phys., vol. 125, 351 (2003)
  • Sedletsky Yu.V., The fourth-order nonlinear Schrodinger equation for the envelope of Stokes waves on the surface of a finite-depth fluid, JETP, vol. 97, 180 (2003)
  • Starostenko V.I., Starkov V.N., On the results of the test of one V.N. Strakhov's hypothesis, Geofiz. Zhurn., vol. 25, 122 (2003) [in Russian].




  • Employees of the Department of Theoretical Physics.

  • Employees of the Department of Theoretical Physics.