Self-Consistent Model of Strong Coupling Theory of Electron Correlations in Disordered Crystals
S. P. Repetsky, O. V. Tretyak, I. G. Vyshivanaya, V. V. Shastun
Taras Shevchenko National University of Kyiv, 60 Volodymyrska Str., UA-01033 Kyiv, Ukraine
Received: 15.03.2012. Download: PDF
The method of the description of electron correlations in the disordered crystals based on a Hamiltonian of many-particle system as well as the diagram technique for calculation of Green’s functions are developed. Electron states of system are featured within the scope of the self-consistent tight-binding multiband model. Processes of scattering of electrons on potentials of the ion cores of different kinds and oscillations of a crystal lattice are considered. The consecutive method for the account of the long-range Coulomb interaction of electrons at different sites of a lattice is offered. The cluster expansion for a density of states, a free energy and an electrical conductivity of the disordered system is obtained. As shown, the contributions of processes of scattering of elementary excitations on clusters decrease with increasing number of sites in a cluster according to some small parameter. Precision of calculation is defined by accuracy of a renormalization of vertex parts of mass operators of electron–electron and electron–phonon interactions as well as by small parameter of the cluster expansion. The nature of spin-dependent electron transport in carbon nanotubes with chromium atoms adsorbed on a surface is found out. As shown, the quantity of spin-dependent transport is related to the relative offset of energy levels of electrons (i.e. to the Coulomb gaps arising in a vicinity of the Fermi level) for different projections of a spin in an external magnetic field.
Keywords: self-consistent tight-binding model, electron correlations, carbon nanotubes doped with Cr atoms, energy spectrum of electrons and phonons, electroconductivity, spin polarization of electric current.
PACS: 63.20.K-, 71.15.Ap, 71.20.Tx, 71.27.+a, 72.10.-d, 72.25.-b, 73.63.Fg
Citation: S. P. Repetsky, O. V. Tretyak, I. G. Vyshivanaya, and V. V. Shastun, Self-Consistent Model of Strong Coupling Theory of Electron Correlations in Disordered Crystals, Usp. Fiz. Met., 13, No. 2: 189—223 (2012), doi: 10.15407/ufm.13.02.189