Condensed Matter Physics, 2020, vol. 23, No. 4, 43714
DOI:10.5488/CMP.23.43714
arXiv:2101.07051
Title:
Electron-hole asymmetry in electron systems with orbital degeneracy and correlated hopping
Author(s):
|
Yu. Skorenkyy
(Ternopil Ivan Puluj National Technical University, 56 Ruska St., 46001 Ternopil, Ukraine),
|
|
O. Kramar
(Ternopil Ivan Puluj National Technical University, 56 Ruska St., 46001 Ternopil, Ukraine),
|
|
Yu. Dovhopyaty
(Ternopil Ivan Puluj National Technical University, 56 Ruska St., 46001 Ternopil, Ukraine)
|
Microscopic models of electronic subsystems with orbital degeneracy of energy states and non-diagonal matrix elements of
electron interactions (correlated hopping) are considered within the configuration-operator approach. Equations for
arbitrary-temperature numerical calculation of the doublon concentration for the integer band filling n=1 at
different forms of the model density of states are derived. The energy spectra obtained within the Green function method are
discussed with special emphasis on the role of correlated hopping in transition from itinerant to localized behavior
observed in vanadium Magneli phases VnO2n-1, transition-metal dichalcogenides
NiS2-xSex,
fulleride AnC60 systems.
Key words:
electron correlations, energy spectrum, orbital degeneracy
|