Structure / Departments / Department for Quantum Statistics
Department for Quantum Statistics
The Department was founded in March 1980. Professor Ivan Oleksandrovych Vakarchuk was the first head of the Department (till September 1984). In 1984-1986 the Department was headed by Doctor of Physical and Mathematical Sciences Yurii Kyrylovych Rudavskyi. Since March 1986 and till April 2016 it was headed by Corresponding Member of the National Academy of Sciences of Ukraine, Professor Ihor Vasylovych Stasyuk. In April 2016 the Department of Quantum Statistics and the Department for Model Spin Systems Theory were unified and Doctor of Physical and Mathematical Sciences Oleg Derzhko became the head of the Department. Meanwhile, there are 17 researchers at the Department. Namely, 5 Doctors of Sciences: I.V.Stasyuk, R.R.Levytskii, O.V.Derzhko, A.M.Shvaika, Ya.Y.Shchur, 10 Candidates of Sciences: R.Ya.Stetsiv, A.P.Moina, B.M.Lisnyi, O.V.Velychko, O.R.Baran, A.S.Vdovych, O.P.Matveyev, G.O.Skorobagatko, O.M.Krupnitska, V.O.Krasnov, as well as Yu.I.Dublenych and D.A.Dobushovskyi. There are 2 Ph.D. students at the Department (V.Ya.Baliha and T.I.Hutak).
Research area of the Department covers a wide range of topics of current condensed matter physics such as the theory of strongly correlated systems (Hubbard, Falicov-Kimball, Heisenberg models), the theory of ultracold gases and intercalated layered crystal structures (Bose-Fermi-Hubbard and Bose-Hubbard models), the studies of classical and quantum spin models, in particular in low dimensions and with frustration, the investigations of ferroelectric ordering and other properties of ferroelectrics including the ones of nanosize. To these ends, various methods of equilibrium and nonequilibrium statistical mechanics are used. For instance, the Green functions approach or exactly solvable models as well as numerical methods such as the electronic density functional method, exact diagonalizations, classical and quantum Monte Carlo etc. All studies are aimed on obtaining the experimentally observable quantities, in particular, magnetization and polarization, specific heat, conductivity and thermoelectric coefficients, susceptibilities, optical spectra and inelastic (Raman) light and x-ray scattering spectra, as well as on constructing phase diagrams for a wide range of models and compounds. A combination of original analytical and numerical methods provides a background for long-lasting scientific collaboration with research groups from Germany, USA, Poland, Slovakia, France, Brazil.
The head of the department - Oleg Derzhko
Oleg Derzhko was born on August 19, 1960 in L’viv. He graduated from the Ivan Franko L’viv University in 1982, earned the Candidate of Physical and Mathematical Sciences degree in 1988, the Senior Researcher in 1998, and the Doctor of Physical and Mathematical Sciences degree in 2004. Since 2003 he headed the Department for Model Spin Systems Theory and since 2016 - the Department for Quantum Statistics. Research interests lie in the area of condensed matter theory and statistical physics.
Phone: (032) 2761978; E-mail: derzhkoicmp.lviv.ua
Research publications
- І.В. Стасюк, Функції Ґріна у квантовій статистиці твердих тіл (Львів, ЛНУ імені Івана Франка, 2013) 392 с., 9 іл.
- Yu.I. Dublenych, Ground states of an Ising model on an extended Shastry-Sutherland lattice and the 1/2-magnetization plateau in some rare-earth-metal tetraborides, Phys. Rev. E 88, 022111 (2013).
- O. Derzhko, J. Richter, O. Krupnitska, T. Krokhmalskii, Frustrated quantum Heisenberg antiferromagnets at high magnetic fields: Beyond the flat-band scenario, Phys. Rev. B 88, 094426 (2013).
- S. Capponi, O. Derzhko, A. Honecker, A.M. Läuchli, J. Richter, Numerical study of magnetization plateaux in the spin-1/2 kagome Heisenberg antiferromagnet, Phys. Rev. B 88, 144416 (2013).
- O. Derzhko, J. Richter, Dispersion-driven ground-state ferromagnetism in a flat-band Hubbard system, Phys. Rev. B 90, 045152 (2014).
- O. Derzhko, J. Richter, M. Maksymenko, Strongly correlated flat-band systems: The route from Heisenberg spins to Hubbard electrons, International Journal of Modern Physics B 29, 1530007 (2015).
- Ya. Shchur, T. Bryk, I. Klevets, A.V. Kityk, Ab initio study of lattice dynamics study of CsH_{2}PO_{4} and CsD_{2}PO_{4} crystals, Computational Materials Science 111, 301 (2016).
- T.P. Devereaux, A.M. Shvaika, K. Wu, K. Wohlfeld, C.J. Jia, Y. Wang, B. Moritz, L. Chaix, W.-S. Lee, Z.-X. Shen, G. Ghiringhelli, L.Braicovich, Directly characterizing the relative strength and momentum dependence of electron-phonon coupling using resonant inelastic x-ray scattering, Phys. Rev. X. 6, 041019 (2016).
- I.V. Stasyuk, V.O. Krasnov, Phase transitions in the hard-core Bose-Fermi-Hubbard model at non-zero temperatures in the heavy-fermion limit, Physica B 511, 109 (2017).
- I.R. Zachek, Ya. Shchur, R.R. Levitskii, A.S. Vdovych, Thermodynamic properties of ferroelectric NH_{3}CH_{2}COOH·H_{2}PO_{3} crystal, Physica B 520, 164 (2017).