Wedge Dyakonov Waves and Dyakonov Plasmons in Topological Insulator Bi2Se3 Probed by Electron Beams.
Wedge Dyakonov Waves and Dyakonov Plasmons in Topological Insulator Bi2Se3 Probed by Electron Beams.
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DOI：
10.1021/acsnano.6b02968
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发表时间：
2016-06
期刊：
影响因子：
17.1
通讯作者：
N. Talebi;C. Ozsoy-Keskinbora;H. Benia;K. Kern;C. Koch;P. V. van Aken
中科院分区：
文献类型：
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作者：
N. Talebi;C. Ozsoy-Keskinbora;H. Benia;K. Kern;C. Koch;P. V. van Aken
Bi 2Se 3最近引起了很多关注，因为据报道它是实现三维拓扑绝缘体的平台。由于这种奇异的特性，它支持表面二维电子气的激发，从而形成狄拉克等离子体。此外，在高于其带隙的较高能量下，Bi 2Se 3的特征在于自然双曲电磁响应，I型和II型双曲行为之间存在有趣的相互作用。然而，仍然没有探索Bi 2Se 3的所有光学模式。在这里，主要使用电子能量损失谱和相应的理论建模，我们调查的状态，Bi 2Se 3维持，在0.8 eV-5 eV的能量范围内的全光子密度。我们表明，在低于1 eV的能量，这种材料也可以支持楔Dyakonov波。此外，在更高的能量下，由于双曲色散，在由Bi 2Se 3制成的诸如波导和谐振器的结构中激发出巨大的光子态密度。
Bi2Se3 has recently attracted a lot of attention because it has been reported to be a platform for the realization of three-dimensional topological insulators. Due to this exotic characteristic, it supports excitations of a two-dimensional electron gas at the surface and, hence, formation of Dirac-plasmons. In addition, at higher energies above its bandgap, Bi2Se3 is characterized by a naturally hyperbolic electromagnetic response, with an interesting interplay between type-I and type-II hyperbolic behaviors. However, still not all the optical modes of Bi2Se3 have been explored. Here, using mainly electron energy-loss spectroscopy and corresponding theoretical modeling we investigate the full photonic density of states that Bi2Se3 sustains, in the energy range of 0.8 eV-5 eV. We show that at energies below 1 eV, this material can also support wedge Dyakonov waves. Furthermore, at higher energies a huge photonic density of states is excited in structures such as waveguides and resonators made of Bi2Se3 due to the hyperbolic dispersion.