Different classes of physical systems with sizeable electron-phonon coupling and lattice distortions present anomalous resistivity behaviors versus temperature. We study a molecular lattice Hamiltonian in which polaronic charge carriers interact with nonlinear potentials provided by local atomic fluctuations between two equilibrium sites. A path-integral model is developed to select the class of atomic oscillations which mainly contributes to the partition function, and the electrical resistivity is computed in a number of representative cases. We argue that the common origin of the observed resistivity anomalies lies in the time retarded nature of the polaronic interactions in the local structural instabilities.
Path Integral Approach to Resistivity Anomalies in Anharmonic Systems
ZOLI, Marco
2001-01-01
Abstract
Different classes of physical systems with sizeable electron-phonon coupling and lattice distortions present anomalous resistivity behaviors versus temperature. We study a molecular lattice Hamiltonian in which polaronic charge carriers interact with nonlinear potentials provided by local atomic fluctuations between two equilibrium sites. A path-integral model is developed to select the class of atomic oscillations which mainly contributes to the partition function, and the electrical resistivity is computed in a number of representative cases. We argue that the common origin of the observed resistivity anomalies lies in the time retarded nature of the polaronic interactions in the local structural instabilities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
