Lattice dynamics effects on small polaron properties

Abstract

This study details the conditions under which strong-coupling perturbation theory can be applied to the molecular crystal model, a fundamental theoretical tool for analysis of the polaron properties. I show that lattice dimensionality and intermolecular forces play a key role in imposing constraints on the applicability of the perturbative approach. The polaron effective mass has been computed in different regimes ranging from the fully antiadiabatic to the fully adiabatic. The polaron masses become essentially dimension independent for sufficiently strong intermolecular coupling strengths and converge to much lower values than those tradition-ally obtained in small-polaron theory. I find evidence for a self-trapping transition in a moderately adiabatic regime at an electron-phonon coupling value of .3. Our results point to a substantial independence of the self-trapping event on dimensionality.

8 pages, 5 figures

References in corpus (6)

• Mobile small polaron
• Polaron Effective Mass, Band Distortion, and Self-Trapping in the Holstein Molecular Crystal Model
• Evolution of a polaron band through the phase diagram of Nd[2-x]Ce[x]CuO[4-y]
• Holstein model in infinite dimensions at half-filling
• Excitation Spectrum of the Holstein Model
• Dynamical properties of the two-dimensional Holstein-Hubbard model in the normal state at zero temperature: A fluctuation-based effective cumulant approach

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• Mass Renormalization in the Su-Schrieffer-Heeger Model
• Bose-Einstein condensation of strongly correlated electrons and phonons in cuprate superconductors
• Polaron Crossover in Molecular Solids
• Polaron Mass and Electron-Phonon Correlations in the Holstein Model
• Polaron self-trapping in a honeycomb net
• Dimensionality Effects on the Su-Schrieffer-Heeger Model
• Path integrals approach to resisitivity anomalies in anharmonic systems
• Spectral Properties of the Su-Schrieffer-Heeger Model
• Non Metallic Transport in Molecular Solids versus Dimensionality
• Particle Path Correlations in a Phonon Bath
• Resistivity peculiarities in systems with lattice distortions