Renormalization of Energy Structure and Oscillation Period in the de Haas–van Alphen Effect at the Strong Intersite Coulomb Interaction

Abstract

The effect of strong intersite Coulomb correlations on the formation of the electron structure of the t – V model has been studied. A qualitatively new result indicating the occurrence of a split-off band of Fermi states has been obtained. The spectral intensity of this band increases with an increase in doping level and is determined by the mean-square fluctuation of occupation numbers. This results in the transformation of the energy structure and the integrated density of states and in a further decrease in state occupation in the quasimomentum space near the Fermi level as compared with Hubbard renormalization. It has been shown that this effect leads to an increase in the area of the quasimomentum space part limited by the Fermi contour and is important for the analysis of the de Haas–van Alphen oscillations in cuprate superconductors.