Research interests:

Dynamical and kinetic properties of metals, dielectrics and low-dimensional systems, spin transport phenomena.

Main results:

1. A new method of the derivation of a quantum kinetic equation based on the Bogolyubov ideas was built for the quantized systems. A number of nonstandard problems on kinetics were solved with the help of this method: (i) The description of the system of electrons interacting with each other and with phonons in a quantized electromagnetic field was given and the theory of the absorption of infrared radiation in metals was built; (ii) The Landau-Lifshitz equation with a relaxation term was derived at a microscopic level (together with V.M. Tsukernik); (iii) The kinetic equation with the finiteness of the life-time of the colliding phonons being taken into account was obtained and the Pomeranchuk problem in the thermal conductivity of dielectrics was solved (together with A.O. Maksimov).
2. A number of kinetic phenomena have been predicted under the conditions when the normal collisions between quasi-particles play a key role: (i) The Poiseuille flow of phonon gas in dielectrics and the hydrodynamic minimum in the temperature dependence of electric resistance of metals and two-dimensional conductors (“Gurzhi effect”) was predicted. Both effects have been found experimentally. One more predicted hydrodynamic effect was also observed experimentally, namely, the predominance of anharmonic terms of an arbitrarily high order in the thermal conductivity of ferrites with temperature decreasing.
3. A method which made it possible to describe a wide range of kinetic phenomena in pure metals at low temperatures, from a general point of view, in terms of non-local diffusion of electrons over the Fermi surface was built. The obtained results  are closely connected with the variety of experimental studies (in collaboration with A.I. Kopeliovich).
4. Qualitatively new mechanisms of electron-phonon and electron-electron relaxation in two-dimensional conducting systems have been predicted (in collaboration with A.I. Kopeliovich and S.B. Rutkevich).

   A number of the results mentioned above are included into the well-known textbooks and monographs on solid state physics, e.g. “L.D.Landau and E.M. Lifshitz, Physical Kinetics, Vol. 10 ” (Pergamon Press, Oxford, 1981); A.A. Abrikosov “Fundamentals of the Theory of Metals” (Elsevier, Amsterdam, 1988); J.S. Blakemore “Solid State Physics” (Cambridge University Press, England, 1985), K.P. Gurov “Fundamentals of the Kinetic Theory” (Nauka, Moscow, 1966) and others.

   Results of the section 2 are presented in the review of R.N. Gurzhi “Hydrodynamic Effects in Solid States” (Uspekhi. Fiz. Nauk, v.94 (1968)).

   Results of the section 3 are presented in the review of R.N. Gurzhi and A.I. Kopeliovich “Low Temperature Electric Conductivity of Pure Metals” (Uspekhi. Fiz. Nauk, v.133 (1981)).

   Results of the section 4 are presented in the review of R.N. Gurzhi, A.I. Kopeliovich, and S.B. Rutkevich “Kinetic Properties of Two-Dimensional Metal Systems” (Adv. Phys., v.36 (1987)).

   The further research activities of Prof. Radii Gurzhi after 1986 see:  Research group of R.N. Gurzhi, A.I. Kopeliovich, A.N. Kalinenko and A.V. Yanovskiy.

List of selected publications:

1. R.N. Gurzhi, A.N. Kalinenko, A.I. Kopeliovich, Electron-Electron Collisions and a New Hydrodynamic Effect in Two-Dimensional Electron Gas, Phys. Rev. Lett., 72, 3872 (1995).
2. R.N. Gurzhi, A.N. Kalinenko, A.I. Kopeliovich, The Theory of Kinetic Effects in Two-Dimensional Degenerate Gas of Colliding Eletrons, Fiz. Nizk. Temp., 23, 58 ( 1997) ) [Low Temp. Phys., 23, 44, (1997)].
3. A.V. Yanovsky, H. Predel., H. Buhmann, R.N. Gurzhi, A.N. Kalinenko, A.I. Kopeliovich, L.W. Molenkamp, Angle-Resolved Spectroscopy of Electron-Electron Scattering in a 2d System, Europhys. Lett., 56, 709 (2001).
4. R.N. Gurzhi, A.N. Kalinenko, A.I. Kopeliovich, A.V. Yanovsky, E.N. Bogachek, and Uzi Landman, Spin-Guide Source of High Spin-Polarized Current, Phys. Rev. B 68, 125113 (2003).
5. R.N. Gurzhi, A.N. Kalinenko, A.I. Kopeliovich, A.V. Yanovsky, E.N. Bogachek, and Uzi Landman, Influence of Electron-Electron Scattering on Spin-Polarized Current States in Magnetic Wrapped Nanowires, Fiz. Nizk. Temp., 29, 809 (2003) [Low Temp. Phys. 29, 606 (2003)].