Electronic Resource
Springer
The European physical journal
94 (1994), S. 147-153
ISSN:
1434-6036
Keywords:
73.40.Hm
;
05.40.+j
;
71.55.Jv
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Velocity correlation functions in the time domain offer a new approach to the dissipative conductivity in the quantum Hall effect at half-filled Landau bands. We describe two methods of calculating these functions directly by wave packet propagation techniques. We address the question whether quantum effects modify the high field diffusion described within the semiclassical percolation picture of the QHE. We investigate a number of random potentials with finite correlation length. Coupling to higher Landau levels leads to damped cyclotron oscillations in the velocity correlation. Besides that, we observe a long time tail Φ(t)∼t −κ with κ≈2.3 for all potential ranges investigated. Within the statistical uncertainty and the time interval considered, this power law is consistent with the semiclassical result obtained by averaging over all cluster sizes. Our findings imply detectable deviations from Drude's law for the AC conductivity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01307666
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