О проекте

The individual project for young scientist, U.S. Civilian Research and Development Foundation (CRDF), the Moldovan Research and Development Association (MRDA) and the Academy of Sciences of Moldova (2008) Abstract: This study is concerned with collective properties of a two-dimensional electron-hole system in a strong perpendicular magnetic field with special attention devoted to the influence of the virtual quantum transitions of interacting particles between the Landau levels. It is shown those virtual quantum transitions of two Coulomb interacting particles from the lowest Landau levels to excited Landau levels with arbitrary quantum numbers n and m and their transition back to the lowest Landau levels in the second order of the perturbation theory result in indirect attraction between the particles supplementary to their Coulomb interaction. The influence of this indirect interaction on the chemical potential of the Bose-Einstein condensed magnetoexcitons and on the ground state energy of the metallic-type electron-hole liquid (EHL) is investigated in the Hartree-Fock approximation. The supplementary electron-electron and hole-hole interactions being averaged with direct pairing of operators increases the binding energy of magnetoexciton and the energy per pair in the EHL phase. The terms obtained in the exchange pairing of operators give rise to repulsion. Together with the Bogoliubov self-energy terms arising from the electron-hole supplementary interaction they both influence in the favor of BEC of magnetoexcitons with small momentum. The new Hamiltonian is concerning the matrix elements of Coulomb interaction between excited landau levels. The motion equations for the summary operators describing the creation and annihilation of magnetoexcitons as well as the density fluctuations of the electron-hole(e-h) plasma will be derived. They suggest the existence of virtual magneto-exciton-plasmon complexes. The Green’s function method in the variant proposed by Zubarev will be used. The description of the Bose-Einstein condensed magnetoexcitons is effectuated using the Keldysh-Kozlov-Kopaev method.