2000/10/20 by Ilaria Meccoli, I. Meccoli, Massimo Capone
Physics and Astronomy · #Mechanical and Optical Resonators #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.63.014303
published as Phys. Rev. B 63, 014303 (2001) · 7 pages, 4 figures, Phys. Rev. B, to appear
arxiv created 2000/10/20 · openalex publication_date 2000/12/11 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the small-polaron problem of a single electron interacting with the lattice for the Holstein model in the adiabatic limit on a comb lattice, when the electron-phonon interaction acts only on the base sites. The ground state properties can be easily deduced from the ones of a linear chain with an appropriate rescaling of the coupling constant. On the other hand, the dynamical properties, that involve the complete spectrum of the system, present an ``exotic'' behavior. In the weak coupling limit the Drude weight (zero-frequency conductivity) is enhanced with respect to its free-case value, contrary to the linear chain case, where for every finite value one has a suppression of the Drude peak. More interestingly, the loss of coherent electron motion and the polaronic localization of the carrier occurs for different coupling values. Thus for intermediate coupling, a different phase appears with large kinetic energy and no coherent motion.