Capacitance Characteristics of a Two-Dimensional Electron System Measured by Charge Accumulation Imaging
Abstract
We study the capacitance between a GaAs-AlGaAs two-dimensional electron system and a metallic tip using a novel highly-stable scanning probe microscope, operable at temperatures down to 280 mK. In our sample geometry, charge enters the 2D layer by tunneling from an underlying 3D contact layer. As a function of bias voltage, the capacitance characteristics form a step structure due to the depletion of the 2D layer. We model the functional form of the capacitance step in this tip-sample configuration and compare these measurements to data acquired with a planar gate electrode in place of the tip.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MARF18011C