Nonlinear magnetotransport phenomena in high-mobility two-dimensional electrons in InGaAs/InP and GaAs/AlGaAs

Article

关键词: ENERGY-LOSS RATES;    MAGNETIC-FIELD;    QUANTUM-WELL;    HETEROSTRUCTURES;    TRANSPORT;    DENSITY;    GASES;    SEMICONDUCTORS;    SPECTROSCOPY;    SUPPRESSION;   

DOI  :  10.1103/PhysRevB.86.115309

来源: SCIE

【 摘 要 】

This paper reports on the observation and analysis of magnetotransport phenomena in the nonlinear differential resistance r(xx) = dV(xx)/dI of high-mobility InxGa1-xAs/InP and GaAs/AlxGa1-xAs Hall bar samples driven by direct current I-dc. Specifically, it is observed that Shubnikov-de Haas (SdH) oscillations at large filling factors invert their phase at sufficiently large values of I-dc. This phase inversion is explained as being due to an electron heating effect. In the quantum Hall effect regime the r(xx) oscillations transform into diamond-shaped patterns with different slopes corresponding to odd and even filling factors. The diamond-shaped features at odd filling factors can be used as a probe to determine spin energy gaps. A zero current anomaly (ZCA) which manifests itself as a narrow dip in the r(xx) (I-dc) characteristics at zero current is also observed. The ZCA effect strongly depends upon temperature, vanishing above 1 K while the transport diamonds persist to higher temperatures. The transport diamonds and ZCA are fully reproduced in a higher mobility GaAs/AlGaAs Hall bar structure confirming that these phenomena reflect intrinsic properties of two-dimensional systems.

【 授权许可】

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