论文标题
II型WEYL半含量MOTE $ _2 $中的拓扑非平凡的频带等离子等离子体
Topologically Nontrivial Interband Plasmons in Type-II Weyl Semimetal MoTe$_2$
论文作者
论文摘要
在许多现实的拓扑材料中，不止一种费米子有助于越过费米水平的电子带，从而导致各种新型现象。在这里，使用动量分辨的非弹性电子散射，我们研究了在II型WEYL SEMIMETAL MOTE $ _2 $中的等离子及其在整个相变的演变，其中Weyl Fermions和琐碎的非递归式费米在TD阶段都对Fermi表面有助于Fermi表面。在高温下1T'相中的一个等离子体模式，在低温下拓扑T $ _d $相中的两个等离子体模式。结合第一架空的计算，我们表明所有等离子体模式都由mote $ _2 $的反向频段之间的带相关性主导。特别是在t $ _d $相位的情况下，由于电子频带由于反转对称性破坏和自旋轨道耦合而分裂，因此，等离子体模式表明了拓扑Weyl Fermions与琐碎的非偏移性电子之间的频带间相关性。我们的工作强调了拓扑材料等离子体中不同种类的载体之间相互作用的重要性。
In many realistic topological materials, more than one kind of fermions contribute to the electronic bands crossing the Fermi level, leading to various novel phenomena. Here, using momentum-resolved inelastic electron scattering, we investigate the plasmons and their evolution across the phase transition in a type-II Weyl Semimetal MoTe$_2$, in which both Weyl fermions and trivial nonrelativistic fermions contribute to the Fermi surface in the Td phase. One plasmon mode in the 1T' phase at high temperature and two plasmon modes in the topological T$_d$ phase at low temperature are observed. Combining with first-priciples calculations, we show that all the plasmon modes are dominated by the interband correlations between the inverted bands of MoTe$_2$. Especially in the T$_d$ phase, since the electronic bands split due to inversion symmetry breaking and spin-orbit coupling, the plasmon modes manifest the interband correlation between the topological Weyl fermions and the trivial nonrelativistic electrons. Our work emphasizes the significance of the interplay between different kinds of carriers in plasmons of topological materials.
