High-frequency conductivity in the fractional quantum Hall regime
- AT and T Bell Lab., Murray Hill, NJ (US)
In this paper surface acoustic wave (SAW) propagation on high quality AlGaAs/GaAs heterostructures is examined in the fractional quantum Hall regime. By measuring the transmitted SAW amplitude and frequency the 2D electron system (2DES) conductivity at the SAW frequency can be deduced and compared to the measured d.c. conductivity. Up to about 500 MHz the SAW derived conductivity does not differ substantially from the measured d.c. conductivity. At higher frequencies some deviations are observed at FQHE and IQHE states. However, at Landau level filling {nu} = 1/2 SAW propagation is markedly different from that observed in the neighboring filling factor range; the response to the SAW is the opposite of that suggested by the d.c. conductivity. In addition, anomalous sound propagation is also observed in the small filling factor range {nu} {approx lt} 1/5, where electron solid formation is suspected. The properties of these distinct SAW anomalies are described and their possible origins discussed.
- OSTI ID:
- 5328554
- Journal Information:
- International Journal of Modern Physics B; (United States), Vol. 6:5; ISSN 0217-9792
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM ARSENIDES
HALL EFFECT
GALLIUM ARSENIDES
AMPLITUDES
FREQUENCY DEPENDENCE
HETEROJUNCTIONS
MHZ RANGE 100-1000
QUANTIZATION
SURFACE PROPERTIES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
FREQUENCY RANGE
GALLIUM COMPOUNDS
JUNCTIONS
MHZ RANGE
PNICTIDES
SEMICONDUCTOR JUNCTIONS
360606* - Other Materials- Physical Properties- (1992-)