Condensed Matter Department, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Adv Mater. 2018 Oct;30(41):e1707628. doi: 10.1002/adma.201707628. Epub 2018 Jun 3.
Exotic electronic states are realized in novel quantum materials. This field is revolutionized by the topological classification of materials. Such compounds necessarily host unique states on their boundaries. Scanning tunneling microscopy studies of these surface states have provided a wealth of spectroscopic characterization, with the successful cooperation of ab initio calculations. The method of quasiparticle interference imaging proves to be particularly useful for probing the dispersion relation of the surface bands. Herein, how a variety of additional fundamental electronic properties can be probed via this method is reviewed. It is demonstrated how quasiparticle interference measurements entail mesoscopic size quantization and the electronic phase coherence in semiconducting nanowires; helical spin protection and energy-momentum fluctuations in a topological insulator; and the structure of the Bloch wave function and the relative insusceptibility of topological electronic states to surface potential in a topological Weyl semimetal.
新颖的量子材料中实现了奇异的电子态。通过对材料的拓扑分类，这一领域发生了革命性的变化。此类化合物在其边界上必然存在独特的状态。通过与第一性原理计算的成功合作，对这些表面态的扫描隧道显微镜研究提供了丰富的光谱特征。准粒子干涉成像方法被证明对于探测表面能带的色散关系特别有用。本文综述了如何通过这种方法探测各种其他基本电子特性。展示了准粒子干涉测量如何导致半导体纳米线中的介观尺寸量子化和电子相位相干；拓扑绝缘体中的螺旋自旋保护和能量-动量涨落；以及 Bloch 波函数的结构和拓扑 Weyl 半金属中拓扑电子态对表面势的相对不敏感性。
