**Igor V.Kukushkin**

Prof. DPhil Igor V. Kukushkin

Member of Russian Academy of Sciences

Igor V. Kukushkin is a renowned Russian physicist, the author of over150 scientific papers, reviews and studies. In 1980 he graduated from Moscow Institute of Physics and Technology and started his scientific career at the Institute of Solid State Physics of the USSR Academy of Sciences where he grew from a trainee to a chief researcher.

I.V.Kukushkin started up his scientific activity with investigation of excitons, exciton molecules and electron-hole liquid in germanium and silicon bulk semiconductors. He was the first to find uncommon deformations of germanium crystals involving instability of electron-hole liquid which enabled observation of the bound state of germanium molecules and study of their properties. I.V.Kukushkin established that in strong magnetic fields such exciton systems reveal quantum-statistical properties of the exciton gas, a precursor of Bose-Einstein condensation of excitons. Those research works were summarized in his PhD thesis in 1983.

I.V.Kukushkin next commenced research into the properties of low-dimension electron systems. He suggested a new magnetooptical method for direct measurement of the two-dimensional electron energy spectrum which he realized on silicon MOS structures. In 1987 I.V.Kukushkin won the Alexander-von-Humboldt scholarship and started his research work in Prof. Klaus von Klitzing’s laboratory at the Max-Planck Institute in Stuttgart, Germany. Using a new class of heterostructures optimized for optical research, I.V.Kukushkin soon received a number of novel results. He pioneered investigation of the two-dimensional electron energy spectrum under the conditions of the quantum Hall effect and discovered the magnetooptical manifestation of the fractional quantum Hall effect observed as a spectral step of two-dimensional electron recombination lines. I.V.Kukushkin was also the first to measure the energy gaps in the quantum Hall effect for various fractional states and reveal their collective nature. His next significant achievement was the magnetooptical investigation of the two-dimensional electron system in the Wigner crystallization mode. Analysis of the recombination kinetics showed that in the ultra-quantum limit, at temperatures below some critical value, the two-dimensional electron system undergoes a phase transition due to formation of the Wigner crystal. I.V.Kukushkin proved that in those conditions the time of two-dimensional electron recombination becomes excessively long and its absolute value allowed for establishing the triangle structure of the electron lattice. In 1990 these achievements were summarized by I.V.Kukushkin in his DPhil thesis *Magetooptics of Two-Dimensional Electrons under the Conditions of the Fractional Quantum Hall Effect and Wigner Crystallization. *

In recent years I.V.Kukushkin has continued the experiments on the properties of low-dimensional electron systems and developed several new experimental techniques, the most significant of them being that of inelastic light scattering and the methods of optical detection of various types of magnetic resonance (cyclotron, dimension, magnetoplasma, spin and nuclear magnetic resonance). By means of nuclear spin optical orientation, I.V.Kukushkin managed to compensate the electron Zeeman energy with the energy of the hyperfine nuclear interaction and discover a new type of excitation, namely, skyrmions, in the quantum Hall effect. I.V.Kukushkin’s recent achievement is the first observation of cyclotron resonance on composite fermions, i.e. new collective quasi-particles in the system of two-dimensional electrons responsible for the quantum Hall effect.

In 1987 I.V.Kukushkin was awarded the Soviet National Prize as the best young scientist. In 1997 he was elected a corresponding member of the Russian Academy of Sciences (General Physics and Astronomy Division). In 1999 he became a professor of the Moscow State University where he supervised over 10 PhD theses and over 15 diploma works. In 2001 V.Kukushkin received the International Max Planck and Alexander-von-Humboldt Research Award for “his pioneer achievements in solid state physics and the fundamental contribution into investigation of the fractional quantum Hall effect”. V.Kukushkin was a second Russian scientist awarded the chief prize of the German scientific society since the prize had been instituted.

Prof. V.Kukushkin is a member of a number of Russian scientific committees such as “Russian Foundation for Basic Research”, “Russian Nanostructure Committee”, “Russian Semiconductor Physics Committee”. For years he has been a member of program committees of various international and Russian conferences. V.Kukushkin is a co-editor (responsible for solid state physics) of *Central European Science Journal* *(CESJ).*