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arXiv 2101.08883cond-mat.mtrl-sci
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基原子对掺杂拓扑绝缘体等离子体激元的控制

Control of Plasmons in Doped Topological Insulators via Basis Atoms

Zhihao Jiang, Henning Schlömer, Stephan Haas

摘要:

拓扑非平凡系统中的集体激发近年来引起了人们的广泛关注。在这里,我们研究等离子体在苏-施里弗-Heeger模型的低能电子带只有部分填充,这样的系统是金属。使用随机相位近似,我们计算的带内和带间的极化函数,并确定从随机相位近似内的介电函数的体等离子体色散。我们发现,亚晶格的基态强烈影响的极化函数,从而控制系统的等离子体激元激发。通过改变这些局部轨道的实空间分离,因此可以经由带内和带间屏蔽过程之间的可调谐折衷来选择性地增强或抑制等离子体激元能量。具体地说,这种机制可以用来稳定无阻尼的高能量等离子体激元,已经在相关模型中报道。我们提出了如何在实验中控制和观察这些影响的方案。

英文摘要:

Collective excitations in topologically non-trivial systems have attracted considerable attention in recent years. Here we study plasmons in the Su-Schrieffer-Heeger model whose low-energy electronic band is only partially filled, such that the system is metallic. Using the random phase approximation, we calculate the intra- and inter-band polarization functions and determine the bulk plasmonic dispersion from the dielectric function within the random phase approximation. We find that the sub-lattice basis states strongly affect the polarization functions and therefore control the system's plasmonic excitations. By varying the real-space separation of these local orbitals, one can thus selectively enhance or suppress the plasmonic energies via a tunable trade-off between intra-band and inter-band screening processes. Specifically, this mechanism can be used to stabilize undamped high energy plasmons that have already been reported in related models. We propose scenarios on how to control and observe these effects in experiments.

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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