Temperature scaling anomalies in quantum Hall plateau transitions with ultra-short period lateral superlattice
K. Kodera, A. Endo, S. Katsumoto, Y. Iye, Y. Ohno, S. Shimomura and S. Hiyamizu
AIP Conf. Proc. 850 1345 (2006)
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Note: LT24
The quantum Hall plateau transitions in GaAs/AlGaAs quantum wells with ultrashort (12 nm) period unidirectional potential modulation have been studied. For the magnetoresistance ¦Ñyy with probe current passed along the stripe, the transition peak width decreases very rapidly as temperature is lowered below 1 K, yielding substantially smaller values of localization length exponent than the canonical cases. By contrast, the ¦Ñxx peaks appear to conform with the canonical scaling behavior. The origin of this anomalous exponent is sought in the directionally correlated disorder characteristic in these systems.