Semiclassical transport in a random magnetic field

✍ Scribed by F Evers; A.D Mirlin; D.G Polyakov; J Wilke; P Wölfle

• Book ID: 104429491
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 102 KB
• Volume: 6
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00193-9

✦ Synopsis

We present a theoretical description of the semiclassical kinetics of two-dimensional fermions in a smoothly varying random magnetic ÿeld (RMF), with emphasis on the composite-fermion (CF) approach to the half-ÿlled Landau level. We demonstrate that the Drude picture of the CF kinetics is only marginally valid at = 1 2 and becomes totally inadequate already at a small deviation from half-ÿlling. We show that the non-Markovian character of the transport leads to a strong positive magnetoresistance xx at small -1 2 . At larger deviations from = 1 2 , the positive magnetoresistance is followed by a sharp fallo of xx ("adiabatic localization"). We show that the AC conductivity xx (!) in the long-range RMF exhibits distinct non-Drude features. In particular, it has a sharp kink [ xx (!)xx (0) ˙|!|] at zero ! and falls o exponentially at higher !.