Theory of the SrTiO3 surface state two-dimensional electron gas
Theory of the SrTiO3 surface state two-dimensional electron gas
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DOI：
10.1103/physrevb.86.125121
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发表时间：
2012-09-17
影响因子：
3.7
通讯作者：
MacDonald, A. H.
中科院分区：
文献类型：
--
作者：
Khalsa, Guru;MacDonald, A. H.
我们提出了一种准二维电子气体（2DEG）系统的理论，当一个大的外电场将载流子吸引到SrTiO3表面时，这种系统会出现在SrTiO3表面附近。我们发现强极化SrTiO3晶格的非线性和非局部筛选在决定2DEG性质中起着至关重要的作用。电子结构总是包含延伸在许多SrTiO3层上的弱束缚块状带。当二维载流子密度超过类似于10(14)cm（-2）时，出现被限制在表面几层内的紧密结合带。
We present a theory of the quasi-two-dimensional electron gas (2DEG) systems that appear near the surface of SrTiO3 when a large external electric field attracts carriers to the surface. We find that nonlinear and nonlocal screening by the strongly polarizable SrTiO3 lattice plays an essential role in determining 2DEG properties. The electronic structure always includes weakly bound bulklike bands that extend over many SrTiO3 layers. At 2D carrier densities exceeding similar to 10(14) cm(-2), tightly bound bands emerge that are confined within a few layers of the surface.