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Surface Acoustic Wave Propagation and Inhomogeneities in Low Density Two-Dimensional Electron Systems Near the Metal-Insulator Transition

L. A. Tracy·J. P. Eisenstein·M. P. Lilly·L. N. Pfeiffer·K. W. West
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Abstract

We have measured the surface acoustic wave velocity shift in a GaAs/AlGaAs heterostructure containing a two-dimensional electron system (2DES) in a low-density regime ($<$ $10^{10}$ cm$^{-2}$) at zero magnetic field. The interaction of the surface acoustic wave with the 2DES is not well described by a simple model using low-frequency conductivity measurements. We speculate that this conflict is a result of inhomogeneities in the 2DES which become very important at low density. This has implications for the putative metal-insulator transition in two dimensions.

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L. A. Tracy, J. P. Eisenstein, M. P. Lilly, L. N. Pfeiffer, K. W. West. 2005-07-04. Surface Acoustic Wave Propagation and Inhomogeneities in Low Density Two-Dimensional Electron Systems Near the Metal-Insulator Transition. https://doi.org/10.1016/j.ssc.2005.10.028

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