Correlation‐induced phase transitions in two‐dimensional electron systems
Correlation‐induced phase transitions in two‐dimensional electron systems
复制标题
二维电子系统中相关引起的相变
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
L. Ioriatti
中科院分区：
文献类型：
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作者：
A. Isihara;L. Ioriatti
摘要：在mosfet的反转层或积累层或半导体-半导体界面中，电子表现出明显的多体效应。提出了一种新的电子相关能理论，使结果适用于较宽的密度范围。得到了所有密度下的基态能量。它是连续收敛的，但在r下标s = 1.414时改变了解析形式。与此变化相关的是可压缩性的散度，发生在r下标s =1.989处。因此，围绕这个r下标s，系统可以被认为是处于类液体状态。在硅反转层的（001）方向上，由于电子的相关性，在高密度下被电子均匀占据的两个谷可能会不均匀地填充。这种不平衡将在r下标s =8.011处引起谷占有相变，这与最近的实验结果非常吻合。在磁场作用下，随着电子密度的减小，磁化率呈非线性增强。当r下标s =13.0时，这种增强变得非常强，超过该值，自旋极化态更有利。
Abstract : The electrons in inversion or accumulation layers of MOSFETs or in semiconductor-semiconductor interfaces show prominent many-body effects. A new theory off the correlation energy is developed for these electrons such that the results are applicable to a wide density range. The ground-state energy is obtained for all densities. It is continuous and convergent, but changes its analytical form at r sub s = 1.414. Associated with this change is a divergence of the compressibility that occurs at r sub s =1.989. Hence, around this r sub s, the system can be considered to be in a liquidlike state. In the (001) direction of silicon inversion layers, the two valleys, occupied equally by the electrons at high densities, may be populated unevenly due to electron correlations. This unbalance will cause a valley occupancy phase transition at r sub s =8.011, in close agreement with a recent experiment. Under a magnetic field, the susceptibility is enhanced nonlinearly when the density of electrons is reduced. This enhancement becomes very strong toward r sub s =13.0, beyond which a spin-polarized state is favored.