Compression for data archiving and backup revisited
Corneliu Constantinescu
SPIE Optical Engineering + Applications 2009
We present detailed numerical calculations of the two-dimensional localization problem in the presence of random flux and discuss the implications of these results to the ν=1/2 anomaly in the quantum Hall systems. In the case where flux disorder breaks the time-reversal symmetry, finite-size scaling of the localization length and the conductance are consistent with a finite region of extended states above a critical energy Ec. For the special case of randomly distributed half-flux quanta per plaquette, where time-reversal invariance is preserved, we find no mobility edge at any nonzero Ec. We observe a crossover from positive magnetoresistance to negative magnetoresistance as potential disorder is increased. These results give qualitative explanation of the striking magnetotransport data at even-denominator filling fractions and suggest an experiment to observe the crossover behavior. © 1993 The American Physical Society.
Corneliu Constantinescu
SPIE Optical Engineering + Applications 2009
A. Gupta, R. Gross, et al.
SPIE Advances in Semiconductors and Superconductors 1990
A. Ney, R. Rajaram, et al.
Journal of Magnetism and Magnetic Materials
Q.R. Huang, Ho-Cheol Kim, et al.
Macromolecules