Browsing by Author "Yang, ZP"

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On the equivalence between magnetic-field-induced phase transitions in the integer quantum Hall effect
(2003-04-01)
Huang, CF
;
Chang, YH
;
Cheng, HH
;
Yang, ZP
;
Wang, SY
Magnetic-field-induced phase transitions in the two-dimensional electron system in a AlGaAs/InGaAs/GaAs heterostructure are studied. Two kinds of magnetic-field-induced phase transitions, plateau-plateau (P-P) and insulator-quantum Hall conductor (I-QH) transitions, are observed in the integer quantum Hall effect regime at high magnetic fields. In the P-P transition, both the semicircle law and the universality of critical conductivities are broken and we do not observe the universal scaling. However, the P-P transition can still be mapped to the I-QH transition by the Landau-level addition transformation, and as the temperature decreases the critical points of these two transitions appear at the same temperature. Our observations indicate that the equivalence between P-P and I-QH transitions can be found by the suitable analysis even when some expected universal properties are invalid. (C) 2003 Elsevier Science Ltd. All rights reserved.