Two-dimensional metal-insulator transition as a percolation transition in a high-mobility electron system.
Two-dimensional metal-insulator transition as a percolation transition in a high-mobility electron system.
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二维金属-绝缘体跃迁作为高迁移率电子系统中的渗流跃迁。
DOI：
10.1103/physrevlett.94.136401
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发表时间：
2004
影响因子：
8.6
通讯作者：
Lucent Technologies
中科院分区：
文献类型：
--
作者：
S. Sarma;M. P. Lilly;E. Hwang;L. Pfeiffer;K. West;J. L. R. C. M. T. Center;D. O. Physics;U. Maryland;Sandia National Laboratories;Bell Laboratories;Lucent Technologies
通过对非掺杂高迁移率n-GaAs异质结中二维电导率的低温密度依赖性的分析，我们认为该二维电子系统中的二维金属-绝缘体转变是一种密度不均匀性驱动的渗透转变，其原因是在随机带电杂质无序背景下屏蔽的击穿.特别是，我们测得的电导率指数约为1.4，在低温下接近4/3的二维渗流指数值，我们的实验数据与我们的系统中存在零温度量子临界点不一致。
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 2D electron 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 approximately 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.