The electron motion along a chain is described by a continuum version of the Su-Schrieffer-Heeger Hamiltonian, in which phonon fields and electronic coordinates are mapped onto the time scale. The path-integral formalism allows us to derive the nonlocal source action for the particle interacting with the oscillators bath. The method can be applied for any value of the e-ph coupling. The path-integral dependence on the model parameters has been analyzed by computing the partition function and some thermodynamical properties from T51 K up to room temperature. A peculiar upturn in the low-temperature heat capacity over temperature ratio ~pointing to a glassy like behavior! has been ascribed to the time-dependent electronic hopping along the chain.
Path Integral Description of a Semiclassical Su-Schrieffer-Heeger Model
ZOLI, Marco
2003-01-01
Abstract
The electron motion along a chain is described by a continuum version of the Su-Schrieffer-Heeger Hamiltonian, in which phonon fields and electronic coordinates are mapped onto the time scale. The path-integral formalism allows us to derive the nonlocal source action for the particle interacting with the oscillators bath. The method can be applied for any value of the e-ph coupling. The path-integral dependence on the model parameters has been analyzed by computing the partition function and some thermodynamical properties from T51 K up to room temperature. A peculiar upturn in the low-temperature heat capacity over temperature ratio ~pointing to a glassy like behavior! has been ascribed to the time-dependent electronic hopping along the chain.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.