| Zugriffsnummer | 20945 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Critical conductance of two dimensional chiral systems with random magnetic flux |
| Autor(in); Institution |
Markoš, Peter; Slovak Academy of Sciences, Institute of Physics, Bratislava, SLOVAKIA
Schweitzer, Ludwig; PSt, Präsidialer Stab, PTB-Braunschweig
|
| Quelle/Jahr | Physical Review B: 76 (2007), 115318-1 - 115318-8 |
| ISSN | 1098-0121 |
| DOI | |
| Verlag | Ridge, NY: APS |
| Klassifikationscode | PACS: 73.23.-b ; PACS: 71.30.+h ; PACS: 72.10.-d |
| Zusammenfassung | The zero temperature transport properties of two-dimensional lattice systems with static random magnetic flux per plaquette and zero mean are investigated numerically. We study the localization properties and the two-terminal conductance and its dependence on energy, sample size, and magnetic flux strength. The influence of boundary conditions and of the oddness of the number of sites in the transverse direction are also studied. For very long strips of finite width, we find a diverging localization length in the middle of the energy band at E=0 and determine ist ciritical exponent ν=0.35 ± 0.03. A previously proposed crossover from a power-law dependence to a logarithmic energy dependence can be excluded from our data, at least for energies E >10-10. For square systems, the sample averaged scale independent critical conductance < gc > turns out to be a function of the amplitude of the flux fluctuations, whereas the variance of the respective conductance distributions appears to be universal. We find a critical conductance < gc > ≊ 1.49e2/h for the strongest possible disorder. |
