The method of density matrices in quantum theory of superconductivity: Boris Bondarev

The book contains a presentation of variational calculation of equilibrium density matrices for multi -partial systems of farmions. Two approaches are considered. The simplest is the approach of the middle field. In the second approximation, there is not only the distribution of particles, but also the correlation function. A method is proposed that makes it possible to use the density matrix to find the energy of valence electrons in the metal. It is proved that the Kulonov’s interaction of electrons in a crystal lattice leads to a model hamiltonian, in which there are two terms. One term describes the attraction of electrons with equal wave vectors, which leads to the formation of electronic pairs. Another terms indicate the repulsion of electrons, the wave vectors of which are equal in size and opposite in the direction. This terms leads to anisotropy in the distribution of electrons through the wave vectors, which indicates the superconductivity of the substance. Fermi function – Diraka, along with model hamiltonian o …

Author
Bondarev Boris Vladimirovich
Publisher
Satellite+, 2015