My main research interest is in theoretical modeling of dynamic processes at solid surfaces. Of particular interest to me is a theretical description of simplest chemical reactions like desorption of adsorbed species when they are irradiated by a light or an electron beam, and the diffusion of the adsorbed species. From the experimental perspective, the only information available about desorption is the type of the probe (light or electrons), its energy, polarization, etc., and the final result: desorption efficiency, kinetic energy and charge of emerging species (atoms, ions, electrons), direction of their flight and, possibly, excitation of their internal degrees of freedom (vibrations, rotations, etc.).
Third generation Synchrotron Radiation sources and modern monochromators allow to use X-ray radiation of unprecedented monochromaticity and intensity to initiate processes induced by electronic transitions in free or adsorbed molecules. Presently, I am involved in theoretical modeling of a detailed scenario of events happening on the femtosecond time scales in free and adsorbed molecules irradiated by an X-ray beam with bandwidth narrower than the lifetime width of the excited state to which the molecule is promoted. Of particular interest are effects of detuning the incident radiation away from the excitation resonance which allows to selectively access various stages of the evolution of a molecule in the excited state. Theoretical modeling for free molecules is an important starting point because comparison of its results with the experimental results for the same molecules adsorbed at the solid surface allows to identify processes specific for surface interactions competing with the events occurring in free molecules.
Surface diffusion is a classic subject studied for over a
century. Its theoretical framework, the diffusion equation, was
provided by Fick in 1855 but only the works of M. Smoluchowski and
A. Einstein at the beginning of the 20-th century provided it with a
microscopic basis. Today, with advanced STM techniques, the mobility
of the surface species can be investigated at a microscopic level by
observing the motion of intividual atoms or group of
atoms. Theoretically, it is still a challenging problem with a few
analytic exact results available. The tool of choice are usually Monte
carlo simulations. My own interest lies in the possibility of
investigating microscopics of surface diffusion using mathematical
models aiming at analytic results.