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Transport parameters of 2D systems derived from microwave transmission experiments

Transportparameter von zweidimensionalen Systemen bestimmt mittels Mikrowellentransmissions-Experimenten
: Brensing, A.; Bauhofer, W.; Köhler, K.

Gershoni, D.:
24th International Conference on the Physics of Semiconductors 1998. Proceedings
Singapore: World Scientific, 1999
ISBN: 981-02-3613-1
4 pp. : Ill., Lit.
International Conference on the Physics of Semiconductors <24, 1998, Jerusalem>
Conference Paper
Fraunhofer IAF ()
III-V Halbleiter; III-V semiconductors; Quantenfilm; quantum wells; electrical measurement; elektrische Messung

This paper reports on low temperature microwave transmission experiments which are performed in high magnetic fields on two-dimensional electron gas (2DEG) systems of heterostructure quantum wells. The main transport parameters of the 2DEG, namely, the electron concentration n(s) the mobility my, and the effective mass m*, are evaluated from the transmitted microwave power. We use two alternative configurations to couple the microwaves into the 2DEG: first the sample fills a rectangular waveguide where the microwaves (26.5-40 GHz) propagate parallel to the magnetic field B (Faraday configuration), second, the microwaves (2-18 GHz) are guided by a coplanar structure mounted on the top of the sample which leads to a Voigt configuration. For both arrangements the microwave power transmitted greatly depends on B according to the respective correlation between microwave transmission and the high frequency conductivity tensor sigma of the 2DEG. Well-pronounced Shubnikov-de Haas oscillations are observed. We compare the discussed methods with respect to experimental feasibility, reproducibility, and data extraction.