Zobrazeno 1 - 10
of 38
pro vyhledávání: '"Velychko, O. P."'
Autor:
Sihver L., Ploc O., Kákona M., Turek K., Kákona J., Šlegl J., Ruban Y., Velychko O., Sommer M., Langer R.
Publikováno v:
EPJ Web of Conferences, Vol 292, p 09001 (2024)
So-called thunderclouds, which are large dark clouds that are able to generate thunder and lightning, can act as natural particle accelerators, producing complex high-energy phenomena such as terrestrial gamma-ray flashes (TGFs) and gamma-ray glows.
Externí odkaz:
https://doaj.org/article/2cdee9dbe63b4c2ba07f9c112a90f00f
Autor:
Stasyuk, I. V., Velychko, O. V.
Publikováno v:
Condens. Matter Phys., 2018, vol. 21, No. 2, 23002
Instabilities resulting in Bose-Einstein condensation and/or modulation of "displacements" in a system of quantum particles described by a two-state Bose-Hubbard model (with an allowance for the interaction between particle displacements on different
Externí odkaz:
http://arxiv.org/abs/1806.09927
Publikováno v:
Condens. Matter Phys., 2015, vol. 18, No. 4, 43004
The spectrum of phonon-like collective excitations in the system of Bose-atoms in optical lattice (more generally, in the system of quantum particles described by the Bose-Hubbard model) is investigated. Such excitations appear due to displacements o
Externí odkaz:
http://arxiv.org/abs/1512.07788
Publikováno v:
Ukrainian Journal of Physics, 2014, Vol. 59, no. 10, pp. 993-1000
The energy spectrum of a system of Bose atoms in the superfluid phase in an optical lattice of the graphene type has been studied. The dispersion laws for the energy bands and the single particle spectral densities are calculated in the random phase
Externí odkaz:
http://arxiv.org/abs/1411.5485
Publikováno v:
Ukrainian Journal of Physics, 2014, Vol. 59, no. 9, pp. 888-900
The band spectrum of bosonic atoms in two-dimensional honeycomb optical lattices with the graphene-type structure has been studied. The dispersion laws in the bands and the one-particle spectral densities are calculated for the normal phase in the ra
Externí odkaz:
http://arxiv.org/abs/1409.8449
Autor:
Stasyuk, I. V., Velychko, O. V.
Publikováno v:
Condens. Matter Phys., 2012, vol. 15, No. 3, 33002:1-9
The Bose-Einstein condensation in the hard-core boson limit (HCB) of the Bose-Hubbard model with two local states and the particle hopping in the excited band only is investigated. For the purpose of considering the non-ergodicity, a single-particle
Externí odkaz:
http://arxiv.org/abs/1210.1424
Autor:
Stasyuk, I. V., Velychko, O. V.
Publikováno v:
Condens. Matter Phys., 2011, vol. 14, No. 1, 13004:1-14
Phase transition into the phase with Bose-Einstein (BE) condensate in the two-band Bose-Hubbard model with the particle hopping in the excited band only is investigated. Instability connected with such a transition (which appears at excitation energi
Externí odkaz:
http://arxiv.org/abs/1103.5662
Autor:
Velychko, O. V., Stasyuk, I. V.
Publikováno v:
I.V. Stasyuk, O.V. Velychko, Condens. Matter Phys., 2009, vol. 12, No. 2, p. 249
Lithium intercalated anatase used in Li-ion batteries has some special features: coexistence of Li-rich and Li-poor phases as well as two possible positions for Li ions in the oxygen tetrahedron. A theoretical description of the compound considering
Externí odkaz:
http://arxiv.org/abs/0907.0687
Autor:
Stasyuk, I. V., Velychko, O. V.
A simple four-sublattice order-disorder model is developed for description of phase transitions and dielectric properties of the Rochelle salt crystal. The model is developed as a generalization of the semimicroscopic Mitsui model. The symmetry prope
Externí odkaz:
http://arxiv.org/abs/cond-mat/0412642
A simple description of thermodynamics of DMAAS and DMAGaS ferroelectric crystals by means of Landau expansion is proposed. Conditions of occurrence of phase transitions are established and their temperatures are obtained. The influence of external h
Externí odkaz:
http://arxiv.org/abs/cond-mat/0001156