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2D Metal-Insulator transition as a percolation transition

S. Das Sarma·M. P. Lilly·E. H. Hwang·L. N. Pfeiffer·K. W. West·J. L. Reno
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Abstract

By carefully analyzing the low temperature density dependence of 2D conductivity in undoped high mobility n-GaAs heterostructures, we conclude that the 2D metal-insulator transition in this system is a density inhomogeneity driven percolation transition due to the breakdown of screening in the random charged impurity disorder background. In particular, our measured conductivity exponent of $\sim 1.4$ approaches the 2D percolation exponent value of 4/3 at low temperatures and our experimental data are inconsistent with there being a zero-temperature quantum critical point in our system.

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S. Das Sarma, M. P. Lilly, E. H. Hwang, L. N. Pfeiffer, K. W. West, J. L. Reno. 2004-06-25. 2D Metal-Insulator transition as a percolation transition. https://doi.org/10.1103/physrevlett.94.136401

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