We study the crossover from quasi-free electron to small polaron in the Holstein model for a single electron by means of both exact and self-consistent calculations in one dimension and on an infinite coordination lattice. We show that the crossover occurs when both strong coupling (λ > 1) and multiphonon (α 2 > 1) conditions are fulfilled leading to different relevant coupling constants (λ) in the adiabatic and (α 2 ) antiadiabatic region of the parameters space. We also show that the self-consistent calculations obtained by including the first electron-phonon vertex correction give accurate results in a sizeable region of the phase diagram well separated from the polaronic crossover.We study the crossover from quasi-free electron to small polaron in the Holstein model for a single electron by means of both exact and self-consistent calculations in one dimension and on an infinite coordination lattice. We show that the crossover occurs when both strong coupling (λ > 1) and multiphonon (α 2 > 1) conditions are fulfilled leading to different relevant coupling constants (λ) in the adiabatic and (α 2 ) antiadiabatic region of the parameters space. We also show that the self-consistent calculations obtained by including the first electron-phonon vertex correction give accurate results in a sizeable region of the phase diagram well separated from the polaronic crossover.

arXiv:cond-mat/9710122Europhysics Letters (EPL)Jun 1, 199855 citations

Numerical study of polaron problem in the adiabatic limit

F. Marsiglio, Zhou Li, C. Blois +1 more

Bulletin of the American Physical SocietyMar 18, 20100 citations

Approximation methods in the polaron theory

Nikolay N. Bogolubov, V. N. Plechko

Rivista Del Nuovo CimentoSep 1, 19889 citations

Electron localization with and without barrier formation

V. V. Kabanov, O. Yu. Mashtakov

The possibility of polaron formation within a model of local electron-phonon interactions is considered. It is shown that, unlike the continuous limit, the solution to the Schro\ifmmode\ddot\else\textasciidieresis\fi{}dinger equation on a two-dimensional lattice in the adiabatic approximation provides evidence for the presence of an energy barrier that separates a small-size polaron and delocalized electronic state. The polaron stability and metastability regions are determined. The possibility of polaron formation in high- ${\mathit{T}}_{\mathit{c}}$ superconductors is discussed.The possibility of polaron formation within a model of local electron-phonon interactions is considered. It is shown that, unlike the continuous limit, the solution to the Schro\ifmmode\ddot\else\textasciidieresis\fi{}dinger equation on a two-dimensional lattice in the adiabatic approximation provides evidence for the presence of an energy barrier that separates a small-size polaron and delocalized electronic state. The polaron stability and metastability regions are determined. The possibility of polaron formation in high-${\mathit{T}}_{\mathit{c}}$ superconductors is discussed.

Physical review. B, Condensed matterMar 1, 1993147 citations

Holstein light quantum polarons

O. S. Barišić

The polaron formation is investigated in the intermediate regime of the Holstein model by using an exact diagonalization technique for the one-dimensional infinite lattice. The numerical results for the electron and phonon propagators are compared with the nonadiabatic weak- and strong-coupling perturbation theories, as well as with the harmonic adiabatic approximation. A qualitative explanation of the crossover regime between the self-trapped and free-particle-like behaviors, not well-understood previously, is proposed. It is shown that a fine balance of nonadiabatic and adiabatic contributions determines the motion of small polarons, making them light. A comprehensive analysis of spatially and temporally resolved low-frequency lattice correlations that characterize the translationally invariant polaron states is derived. Various behaviors of the polaronic deformation field, ranging from classical adiabatic for strong couplings to quantum nonadiabatic for weak couplings, are discussed.The polaron formation is investigated in the intermediate regime of the Holstein model by using an exact diagonalization technique for the one-dimensional infinite lattice. The numerical results for the electron and phonon propagators are compared with the nonadiabatic weak- and strong-coupling perturbation theories, as well as with the harmonic adiabatic approximation. A qualitative explanation of the crossover regime between the self-trapped and free-particle-like behaviors, not well-understood previously, is proposed. It is shown that a fine balance of nonadiabatic and adiabatic contributions determines the motion of small polarons, making them light. A comprehensive analysis of spatially and temporally resolved low-frequency lattice correlations that characterize the translationally invariant polaron states is derived. Various behaviors of the polaronic deformation field, ranging from classical adiabatic for strong couplings to quantum nonadiabatic for weak couplings, are discussed.

arXiv:cond-mat/0602260Feb 10, 20060 citations

{\mathit{T}}_{\mathit{c}}

superconductors is discussed.