The Observation of Percolation-Induced 2D Metal-Insulator Transition in a Si MOSFET
| Autor: | Tracy, L. A., Hwang, E. H., Eng, K., Eyck, G. A. Ten, Nordberg, E. P., Childs, K., Carroll, M. S., Lilly, M. P., Sarma, S. Das |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 79, 235307 (2009) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.79.235307 |
| Popis: | By analyzing the temperature ($T$) and density ($n$) dependence of the measured conductivity ($\sigma$) of 2D electrons in the low density ($\sim10^{11}$cm$^{-2}$) and temperature (0.02 - 10 K) regime of high-mobility (1.0 and 1.5 $\times 10^4$ cm$^2$/Vs) Si MOSFETs, we establish that the putative 2D metal-insulator transition is a density-inhomogeneity driven percolation transition where the density-dependent conductivity vanishes as $\sigma (n) \propto (n - n_p)^p$, with the exponent $p \sim 1.2$ being consistent with a percolation transition. The `metallic' behavior of $\sigma (T)$ for $n > n_p$ is shown to be well-described by a semi-classical Boltzmann theory, and we observe the standard weak localization-induced negative magnetoresistance behavior, as expected in a normal Fermi liquid, in the metallic phase. Comment: 6 pages, 5 figures; extended version (accepted to Phys. Rev. B) |
| Databáze: | arXiv |
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