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arXiv 1302.1874cond-mat.str-el
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Kondo绝缘体中相互作用驱动的拓扑态跃迁

Interaction-driven transition between topological states in a Kondo insulator

Jan Werner, Fakher F. Assaad

摘要:

重费米子材料自然地结合了强自旋轨道相互作用和电子相关。当每个杂质自旋只有一个传导电子时,相干重费米子态是绝缘的。这种近藤绝缘态最近被认为属于量子自旋霍尔态。出于这一猜想和最近的实验实现这种状态,我们研究了近藤绝缘体与自旋轨道耦合的模型。使用DMFT,我们观察到两个不同的拓扑状态之间的相互作用驱动的过渡,由体隙的关闭和Z2拓扑不变量的同时变化表示。在大的相互作用强度,我们发现一个拓扑重费米子状态,其特征在于强重整化的重体带,托管一对零能量边缘模式。该模型允许详细了解的温度依赖性的单粒子谱函数,特别是能量尺度,在该尺度下观察到的外观内的散装间隙的边缘状态。

英文摘要:

Heavy fermion materials naturally combine strong spin-orbit interactions and electronic correlations. When there is precisely one conduction electron per impurity spin, the coherent heavy fermion state is insulating. This Kondo insulating state has recently been argued to belong to the class of quantum spin Hall states. Motivated by this conjecture and a very recent experimental realization of this state, we investigate a model for Kondo insulators with spin-orbit coupling. Using DMFT, we observe an interaction-driven transition between two distinct topological states, indicated by a closing of the bulk gap and a simultaneous change of the Z2 topological invariant. At large interaction strength we find a topological heavy fermion state, characterized by strongly renormalized heavy bulk bands, hosting a pair of zero-energy edge modes. The model allows a detailed understanding of the temperature dependence of the single particle spectral function and in particular the energy scales at which one observes the appearance of edge states within the bulk gap.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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