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Information × Registration Number 0221U100595, 0120U102252 , R & D reports Title The influence of internal degrees of freedom of particles on the physical characteristics of quantum systems near phase transitions. popup.stage_title Head Girka Igor O., Доктор фізико-математичних наук Registration Date 07-01-2021 Organization V.N. Karazin Kharkiv National University popup.description2  The object of the study was the cooled rarefied gases of atoms of alkali and alkaline earth-like metals, which, depending on the atomic isotope, are subject to Bose-Einstein or Fermi-Dirac statistics, optical traps and optical lattices generated by lasers. The objective of the research was to identify unique equilibrium and dynamic states of matter under extreme conditions, to establish prospects for the use of internal degrees of freedom of system elements to enhance the effects of electromagnetic response, violation of continuous symmetries and associated phase transformations. The system of many interacting particles with a unit spin in the context of homogeneous ultracold gases is investigated. On the basis of symmetrical considerations, a multiparticle Hamiltonian of pair interaction is constructed, which includes eight generators of the SU (3) group, which are associated with these parameters of the description. It is shown how the quadrupole degrees of freedom included in the Hamiltonian modify the ground state and spectra of single-particle excitations in comparison with the spectra obtained earlier on the basis of the bilinear Hamiltonian by spin operators, which does not take into account quadrupole degrees of freedom. The issue of taking into account the local nature of the interaction to obtain the correct spectra of single-particle excitations is discussed. The problem of the emergence of equilibrium low-temperature phases in quantum mixtures of alkaline earth-like atoms with many degrees of freedom in mill-dependent optical lattices is formulated and solved with the help of the dynamic theory of the mean field. Using ytterbium-173 atoms as an example. The phase diagram of the complete Hamiltonian with parameters close to the experimental ones is calculated and constructed. Product Description popup.authors Bulakhov Mykyta S Vozniuk Dmytro V Peletminskii Oleksander S Slyusarenko Yurii V Sotnikov Andrii H Yunakov Mykola M popup.nrat_date 2021-03-17 Close