Green's and spectral functions of small Fröhlich polaron
Department of Physics, Loughborough University - Loughborough LE11
Accepted: 17 May 2000
According to recent quantum Monte Carlo simulations, the small polaron theory is practically exact in a wide range of the long-range (Fröhlich) electron-phonon coupling and adiabatic ratio. Applying Lang-Firsov transformation, we derive a single-particle Green's function describing the propagation of small Fröhlich polaron. One- and two-dimensional spectral functions are studied by expanding Green's function perturbatively. Remarkably, the coherent spectral weight ( Z ) and effective mass (Z') renormalisation exponents are found to be different with , which can explain a small coherent spectral weight and a relatively moderate mass enhancement in oxides.
PACS: 74.20.Mn – Nonconventional mechanisms (spin fluctuations, polarons and bipolarons, resonating valence bond model, anyon mechanism, marginal Fermi liquid, Luttinger liquid, etc.) / 74.20.-z – Theories and models of superconducting state / 74.25.Jb – Electronic structure
© EDP Sciences, 2000