Magnetic impurities in the Kane-Mele model
Magnetic impurities in the Kane-Mele model
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DOI：
10.1103/physrevb.88.075110
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发表时间：
2013-08-05
影响因子：
3.7
通讯作者：
Assaad, Fakher F.
中科院分区：
文献类型：
--
作者：
Goth, Florian;Luitz, David J.;Assaad, Fakher F.
量子阱中自旋霍尔效应的实现导致了对二维拓扑绝缘体边缘态性质的大量研究。这些边缘态构成了一类一维液体，称为螺旋液体，其中电子的自旋量子化轴与其动量相关联。与一维导体相比，磁性杂质——低于近藤温度——不会阻碍传输，人们期望电流能绕过杂质。为了研究这一现象，我们考虑将单杂质安德森模型嵌入到具有512 x 80个位点的Kane-Mele带的边缘，并使用数值精确的连续时间量子蒙特卡罗方法来研究近藤效应。我们提出了有关杂质和体系光谱性质的温度依赖性的结果，这些结果显示了系统在安德森模型的各种制度下的行为。利用自旋-自旋相关函数的空间行为可以得到与单粒子谱函数互补的视图。在这里，我们展示了在杂质附近的边缘通道中的特征代数衰减。
The realization of the spin-Hall effect in quantum wells has led to a plethora of studies regarding the properties of the edge states of a two-dimensional topological insulator. These edge states constitute a class of one-dimensional liquids, called the helical liquid, where an electron's spin quantization axis is tied to its momentum. In contrast to one-dimensional conductors, magnetic impurities-below the Kondo temperature-cannot block transport and one expects the current to circumvent the impurity. To study this phenomenon, we consider the single-impurity Anderson model embedded into an edge of a Kane-Mele ribbon with up to 512 x 80 sites and use the numerically exact continuous time quantum Monte Carlo method to study the Kondo effect. We present results on the temperature dependence of the spectral properties of the impurity and the bulk system that show the behavior of the system in the various regimes of the Anderson model. A view complementary to the single-particle spectral functions can be obtained using the spatial behavior of the spin-spin correlation functions. Here we show the characteristic, algebraic decay in the edge channel near the impurity.