Scanning Electrometer: Mapping of Electric Potential and Its Fluctuation

• Yukio Kawano

Abstract

We present a scanning sensor for imaging spatial distributions of electric potential and its temporal fluctuation. This technique utilizes a scanning electrometer based on a two-dimensional electron gas (2DEG) transistor in GaAs/AlGaAs. The detection mechanism is that local electric potential is detected through gate effects for the 2DEG sensor via capacitive coupling with a sample. Using this technique, we have demonstrated mapping of the electric potential distribution for another 2DEG sample in a GaAs/AlGaAs interface. In addition, by measuring local voltage fluctuations with the electrometer, we have been able to produce the first image of a noise-voltage distribution in a 2DEG sample. When this potential imaging technique is combined with terahertz-wave imaging, the resulting system works as a strong tool for investigating electron transport in the energy and space domains. As application of this system, we show separate imaging of intra- and inter-level scattering distributions in quantum Hall conductors.

Journal

• Japanese Journal of Applied Physics

  Japanese Journal of Applied Physics 49 (8S3), 08LA02-, 2010-08-01

  IOP Publishing

Keywords

• General Physics and Astronomy
• General Engineering

Details

• CRID: 1360566396809105280
• NII Article ID: 210000069123
• DOI: 10.1143/jjap.49.08la02
• ISSN: 13474065
• ISSN: 00214922
• Web Site: https://iopscience.iop.org/article/10.1143/JJAP.49.08LA02
• Web Site: https://iopscience.iop.org/article/10.1143/JJAP.49.08LA02/pdf
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