2000/10/28 by M. Acquarone, Marcello Acquarone, Mario Cuoco +2
Materials Science · Mathematics · Physics and Astronomy · #Atomic orbital #Condensed matter physics #Electron #Electronic correlation #Gaussian #Ground state #Hamiltonian (control theory) #Hubbard model #Lattice (music) #Mathematics #Organic and Molecular Conductors Research #Phonon #Physics #Physics of Superconductivity and Magnetism #Polaron #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #Wannier function #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.63.035110
published as Physical Review B 63, 035110 (2001) · 13 pages, 11 figures. To appear in Physical Review B
arxiv created 2000/10/28 · openalex publication_date 2001/01/02 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the complete extended Hubbard-Holstein Hamiltonian on a four-site chain with equally spaced sites, with spacing-dependent electronic interaction parameters evaluated in terms of Wannier functions built from Gaussian atomic orbitals. By successive application of generalized displacement and squeezing transformations, an effective polaronic Hamiltonian is obtained, containing a purely phonon-induced, long-range intersite charge interaction. The phase diagrams for N=1, 2, 3, and 4 electrons are determined by variational minimization of the sum of the electronic and the phononic energy, paying special attention to the effects of the above-mentioned phonon-induced long-range interaction. To characterize the physics of each ground state, we evaluate how variations of the site spacing affect the behavior of several correlation functions of experimental interest, with the aim of representing lattice deformation effects, either spontaneous or induced by external pressure.