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Transport and Percolation in a Low-Density High-Mobility Two-Dimensional Hole System

2007; American Physical Society; Volume: 99; Issue: 23 Linguagem: Inglês

10.1103/physrevlett.99.236402

1092-0145

Michael J. Manfra, E. H. Hwang, S. Das Sarma, L. N. Pfeiffer, K. W. West, A. M. Sergent,

Theoretical and Computational Physics

We present a study of the temperature and density dependence of the resistivity of an extremely high quality two-dimensional hole system grown on the (100) surface of GaAs. For high densities in the metallic regime ($p\ensuremath{\gtrsim}4\ifmmode\times\else\texttimes\fi{}{10}^{9}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$), the nonmonotonic temperature dependence ($\ensuremath{\sim}50--300\text{ }\text{ }\mathrm{mK}$) of the resistivity is consistent with temperature dependent screening of residual impurities. At a fixed temperature of $T=50\text{ }\text{ }\mathrm{mK}$, the conductivity versus density data indicate an inhomogeneity driven percolation-type transition to an insulating state at a critical density of $3.8\ifmmode\times\else\texttimes\fi{}{10}^{9}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$.