The Faculty of Physics

Ruslan V. Vovk

    Dean, Acting Head of Department of Low-Temperature hysics, Doctor of Sciences and Professor in the School of Physics of V.N. Karazin Kharkov National University

    Telephone:+38 (057) 707-53-83;
    Address: V. N. Karazin Kharkiv National University,
    Department of Physics, 6 Svobody Square, Kharkov 61022;
    -mail: ruslan.v.vovk@univer.kharkov.ua

   Dr. Ruslan V. Vovk is the Doctor of Sciences and Professor in the School of Physics of V.N. Karazin Kharkov National University (KhNU). In 1990, completed postgraduate studies at the Low Temperature Physics Department of M. Gorky Kharkov State University.
   He received his Diploma (1990), Ph.D (1998) and D.Sc. in physics and mathematics (2008) from the School of Physics of the Kharkov State University (now V.N. Karazin Kharkov National University), Ukraine.
   He works in the Low Temperature Physics Department of KhNU since 1990. He was appointed as engineer (1990-1994), junior researcher (1994-1997), and scientific researcher (1997-1999) and as Senior Researcher (1999-2008). As from 2008 to 2012 he was appointed as Professor in both, Low Temperature Physics and Experimental Physics Departments at KhNU. Since 2012 Head of Low Temperature Physics Department V.N. Karazin Kharkov National University.
   Dr. Vovk has also been appointed as Professor in the Physics Department at the Ukrainian State Academy of Railway Transport (USART) in Kharkov (since 2000). He served as the Head (Chair) of the General Technical Department and since 2008 he serves as the Head (Chair) of the Physics Department at the USART (Kharkov). He is member of the Editorial Board of the Journal “Vestnik – Bulletin” of V.N. Karazin Kharkov National University, in the series: “Physics”. Member of two Specialized scientific councils (at V.N. Karazin Kharkov National University and B.I. Verkin FTINT of Ukrainian Academy of Sciences) on candidate and doctoral theses.
   He developed and currently teaches the following four courses: 1. “Medical and Biological Physics”, 2. “Physics of superconductivity”, 3. “Physics of quantum liquids” and 4. “General Physics”. He has supervised and presently supervises a number of Ph.D students.
   His scientific activities cover a wide range of materials science with the main focus being in high temperature superconductivity and the study of the evolution of anisotropic systems of quasi-particle excitations in quantum fluids. He has won twice (in 1994 and 1997) the Cabinet of Ministers of Ukraine grant for young scientists. He was a postdoctoral research Fellow at the University of Exeter (UK), from 2002 to 2004 at the world famous "quantum fluids" group of Prof. A.F.J. Wyatt FRS. His research was on temporal and spatial evolution of anisotropic boson systems in superfluid 4He. He developed the scientific foundations in a new field of low and very low temperatures physics: the dynamics of subsystems of quasi-particle excitations in structural and kinematic anisotropy. He first developed the experimental technique of detecting separately the high-and the low-energy phonons in superfluid quantum liquids, and set the patterns of the generation of “hot” h-phonons at various stages of distribution of “cold”- l-phonon pulse. He first proposed and implemented a method for studying the processes of interaction of several independent phonon beams when they collide in superfluid 4He and observed the phenomenon of generating "hot lines" at very low temperatures. For his work in the above theme was awarded a special medal of the European Scientific Society.
   Main international collaborations: Imperial College London (UK), University of Exeter (UK), Max-Planck Institute (D), IMS NCSR DEMOKRITOS (GR), Instituto Superior Dom Afonso III (P), University New-Brunswick (CAN).
   He is author and co-author of more than 150 papers. He has contributed in international conference more than 50 presentations. For his scientific and academic work, he was awarded 5 times with diplomas from Russian Academy of Science and in 2008 was the first recipient of the prestigious Karazin Prize and in 2011 - Karazin Prize. Diploma of "High School of Kharkov - the best names" in 2012.

Selected papers (in peer- reviewed journals):

1. Vovk R.V., Williams C.D.H., and Wyatt A.F.G. Interactions between Sheets of Phonons in Liquid 4He // Phys. Rev. Lett. -2003. -Vol. 91, 23. -. 235302 (1-4).
2. Vovk R.V., Williams C.D.H., and Wyatt A.F.G. High-energy phonon pulses in liquid 4He // Phys. Rev. B. -2004. -Vol. 69, 14. -. 144524 (1-10).
3. Smith D.H.S., Vovk R.V., Williams C.D.H., and Wyatt A.F.G. Pressure dependence of phonon interactions in Liquid 4He // Phys. Rev. B. -2005. -Vol. 72, 5. -. 054506 (1-7).
4. Smith D.H.S., Vovk R.V., Williams C.D.H., and Wyatt A.F.G. Interactions between phonon sheets in superfluid helium // New Journal of Physics. -2006. -V.8, 8. -. 128-147.
5. Vovk R.V., Obolenskii M.A., Zavgorodniy A.A., Bondarenko A.V., Goulatis I.L., Chroneos A.I. Excess conductivity and pseudo-gap state in YBCO single crystals slightly doped with Al and Pr // J Mater Sciences: Mater in Electron. -2007. Vol.18. -P. 811-815.
6. R.V.Vovk, M.A.Obolenskii, A.A.Zavgorodniy, A.V.Bondarenko, I.L.Goulatis, A.V.Samoilov, A.I.Chroneos/ Transport anisotropy and pseudo-gap state in oxygen deficient ReBa2Cu3O7-δ (Re=Y, ) single crystals.// Journal of Alloys and Compaunds. -2008. -464, P. 58-66.
7. R.V. Vovk, M.A. Obolenskii, A.A. Zavgorodniy, I.L. Goulatis, V.I. Beletskii, A. Chroneos. Structural relaxation, metal-to-insulator transition and pseudo-gap in oxygen deficient Ba2Cu3O7-δ single crystals // Physica C. – 2009. –V.469. – P. 203-206.
8. R. V. Vovk, A. A. Zavgorodniy, M. A. Obolenskii, I. L. Goulatis, A. Chroneos. Influence of high pressure on the temperature-dependence of the pseudo-gap in oxygen deficient YBa2Cu3O7-δ single crystals. // Modern Physics Letters B (MPLB). -2010. – V.24,22. –P. 2295-2301.
9. R. V. Vovk, Z. F. Nazyrov, M. A. Obolenskii, I. L. Goulatis, A. Chroneos Phase separation in oxygen deficient Ba2Cu3O7-δ single crystals: effect of high pressure and twin boundaries. // Philosophical Magazine V. 91, 17, 11 (2011), P. 2291-2302.
10. Chroneos A., Vovk R.V., Goulatis I. / Oxygen self-diffusion in apatites // Chemical Monthly (2012) –V.143. –P.345-353. REVIEW.
11. R. V. Vovk, G.Ya. Khadzhai, Z. F. Nazyrov, I. L. Goulatis, A. Chroneos / Relaxation of the normal electrical resistivity induced by high-pressure in strongly underdoped YBa2Cu3O7-δ single crystals. // Physica B 407 (2012) – 4470-4472.
12. R. V. Vovk, Z. F. Nazyrov, I. L. Goulatis, A. Chroneos / Metal-to-insulator transition in Y1-xPrxBa2Cu3O7-δ single crystals with various praseodymium content // Physica C 485 (2013) –P.89-91.