Search academic texts

Information × Registration Number 0222U003433, 0119U100176 , R & D reports Title Spin-dependent processes in crystals and nanostructures, development the projective representation methods of symmetry groups for their interpretation. popup.stage_title Head Gubanov Viktor , Доктор фізико-математичних наук Registration Date 22-03-2022 Organization Taras Shevchenko National University of Kyiv popup.description2 Object of research - Crystals of hexagonal and cubic syngony, linear π-electron conjugate systems, one- and two-dimensional carbon graphite structures and their inorganic analogues, nanocomposites based on them. The aim of the work is to study the energy spectra of elementary excitations in crystals, nanostructures and nanocomposites and their interpretation with involvement advanced methods for constructing projective representations of symmetry groups and methods of quantum chemistry. Research methods - methods of theory of symmetry groups, Raman spectroscopy, spectrophotometry, photoluminescence, methods of quantum chemistry. The correlation of vibrational modes, their dispersion and dispersion dependences of electronic excitations without taking into account the electron spin and taking it into account in single-layer graphene and graphite crystals, hexagonal boron nitride crystals and cubic crystals of diamond, germanium and silicon are studied. To interpret such correlations, the methods of the theory of projective representations of point and spatial symmetry groups were used for the first time. Correlations of energy spectra of symmetry oscillatory groups are determined. The correlations of the energy spectra of oscillatory and electronic excitations and the conditions of compatibility of irreducible projective representations in the descriptions of quantum states for different points of their Brillouin zones are determined. For projective representations of all projective classes of hexagonal and cubic systems, standard factor systems were built for the first time, including factor systems for electronic states were determined for the first time, with the help of which correct spinor multiplication tables were found for the first time, ie multiplication tables of elements in double (covering) symmetry groups.  Product Description popup.authors Bilyy Mykola M. Bashmakova Nataliia V. Gryn Dmytro V. Korniyenko Mykola Ye. Navozenko Oleksandr M. Naumenko Antonina Р. Sabov Maksym M. popup.nrat_date 2022-03-22 Close