ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The dc electrical conductivity above the Peierls-transition temperature Tc of quasi-one-dimensional (1D) organic metals is calculated by an ab initio single-particle theory based on the Kubo–Mori formalism. The respective inverse relaxation time in this approach is calculated numerically. The theory allows for a reliable reproduction of experimentally derived normalized conductivity curves of highly anisotropic organic metals. The applicability of the model is reduced with decreasing anisotropy. Phenomenologically it can be shown that a T−2 law of decay of the dc electrical conductivity above Tc is conventionally connected with large anisotropies. Decreasing anisotropy leads to T−n curves, where n is sizeably smaller than 2. The theoretical approach reproduces a T−n, n≈2, law of decay in the framework of one-phonon electron scattering processes. Therefore it is suggested that the deviations from the T−1 behavior of conventional three-dimensional metals is caused by the strong Kohn anomaly in 1D systems. The influence of the electron–phonon coupling and the Debye temperature on the analytic structure of the normalized dc electrical conductivity curves has been studied. A general theoretical description is suggested to account for the influence of electronic correlations on the magnitude of the electron–phonon coupling as well as on the Peierls-transition temperature. It is shown qualitatively that the organic metals belong to a class of valence fluctuating systems where charge fluctuations are conserved also in the limit of strong electronic correlations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.456737
