A tunable and unidirectional one-dimensional electronic system Nb2n+1SinTe4n+2
A tunable and unidirectional one-dimensional electronic system Nb2n+1SinTe4n+2
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可调谐单向一维电子系统Nb2n 1SinTe4n 2
DOI：
10.1038/s41535-020-0238-0
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发表时间：
2020
影响因子：
5.7
通讯作者：
Jia Jin-Feng
中科院分区：
文献类型：
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作者：
Zhu Zhen;Li Si;Yang Meng;Nie Xiao-Ang;Xu Hao-Ke;Yang Xu;Guan Dan-Dan;Wang Shiyong;Li Yao-Yi;Liu Canhua;Mao Zhi-Qiang;Xu Nan;Yao Yugui;Yang Shengyuan A.;Shi You-Guo;Zheng Hao;Jia Jin-Feng
一维电子系统是承载电荷密度波、Su-Schrieffer-Heeger （SSH）拓扑态和孤子、Tomonaga-Luttinger液体等新物理的通用平台。本文系统地研究了层状成分可调化合物Nb2n+1SinTe4n+2（n= 1 - 5）的表面电子性质，该化合物在n= 1 （Nb3SiTe6）时被预测为节线半金属。通过扫描隧道显微镜/光谱学，我们观察到化合物表面形成了一维链。我们发现，随着n的增加，链之间的距离变大，并且在≥3的化合物中出现1D电子态。我们的第一性原理计算表明，nb3site6中的节点线和高硒晶体中的一维电子态实际上来自相同的带，这些带受到相同的非对称对称性的保护。此外，我们可以通过简单的SSH型图来理解这些结构和组成如此复杂的系列化合物的电子态演化。我们的实验展示了一个可调谐的单向一维电子系统，为探索有趣的一维电子物理提供了一个具体的平台，并将为未来的凝聚态物理、材料科学和纳米技术研究提供丰富的机会。
One dimensional (1D) electronic system is a versatile platform hosting novel physics, such as charge density wave, Su-Schrieffer-Heeger (SSH) topological state and solitons, Tomonaga-Luttinger Liquid etc. Here, we systematically study the surface electronic properties on layered composition-tunable compounds Nb2n+1SinTe4n+2(n= 1–5), which is predicted to be a nodal-line semimetal whenn= 1 (Nb3SiTe6). Via scanning tunneling microscopy/spectroscopy, we observe 1D chains formed on the surface of the compounds. We uncover that with the increasing ofn, the distance between the chains becomes larger, and the 1D electronic state is developed in the compounds withn≥ 3. Our first-principle calculations reveal that the nodal-line in Nb3SiTe6and the 1D electronic state in the crystals with highernin fact arise from the same bands, which are protected by the same nonsymmorphic symmetry. Furthermore, we can understand the evolution of the electronic states on these series of compounds with such complicated structures and compositions based on a simple SSH type picture. Our experiment demonstrates a tunable and unidirectional 1D electronic system, which offers a concrete platform for the exploration of intriguing 1D electron physics and will enrich the opportunity for future condensed matter physics, material science and nanotechnology researches.