Low-frequency fluctuations in the ac conductivity of a chain with impurity
| Autor: | Zheng Zhao Bo |
|---|---|
| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Physical Review B. 42:8923-8927 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.42.8923 |
| Popis: | This paper presents a study of ac-conductivity fluctuations for a finite chain of 500 atoms with 10% impurity at zero temperature and low frequency. The average ac conductivity \ensuremath{\sigma}\ifmmode\bar\else\textasciimacron\fi{}(\ensuremath{\Elzxh}\ensuremath{\omega}) as a function of frequency \ensuremath{\Elzxh}\ensuremath{\omega} has been calculated by averaging over 500 configurations. Fluctuations from configuration to configuration vary greatly. Since the number of configurations is sufficiently large, the average ac conductivity reaches the desired limit, and consequently \ensuremath{\sigma}\ifmmode\bar\else\textasciimacron\fi{} is a smooth function of \ensuremath{\Elzxh}\ensuremath{\omega} and is significant. The statistical distribution curves of the ac conductivity for first-order transitions have been obtained to study the fluctuations. We have found that the fluctuations reach a maximum when the strength of the impurity assumes some intermediate value. These results can be explained by localization and the distance between the amplitude-maximum position of two allowed transition states. |
| Databáze: | OpenAIRE |
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