Direct visualization of a two-dimensional topological insulator in the single-layer 1T′-WTe2
Direct visualization of a two-dimensional topological insulator in the single-layer 1T′-WTe2
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单层 1Tâ²-WT e2 中二维拓扑绝缘体的直接可视化
DOI：
10.1103/physrevb.96.041108
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发表时间：
2017-07-07
影响因子：
3.7
通讯作者：
Li, Shao-Chun
中科院分区：
文献类型：
--
作者：
Jia, Zhen-Yu;Song, Ye-Heng;Li, Shao-Chun
我们用分子束外延（MBE）方法在石墨化的6 H-SiC（0001）衬底上生长了近自支撑的单层1 T ′-WTe_2薄膜，并用扫描隧道显微镜/光谱仪（STM/STS）对其电子结构进行了表征。证实了单层WTe 2岛外围拓扑边态的存在。令人惊讶的是，在费米能级的体带隙和绝缘行为也被发现在单层WTe 2在低温下，这可能是与一个不相称的电荷顺序转变。二维拓扑绝缘体（2D TI）在单层过渡金属硫属化物中的实现为进一步探索2D TI的物理和相关应用提供了一个有前途的平台。
We have grown nearly freestanding single-layer 1T'-WTe2 on graphitized 6H-SiC(0001) by using molecular beam epitaxy (MBE), and characterized its electronic structure with scanning tunnelingmicroscopy/spectroscopy (STM/STS). The existence of topological edge states at the periphery of single-layer WTe2 islands was confirmed. Surprisingly, a bulk band gap at the Fermi level and insulating behaviors were also found in single-layer WTe2 at low temperature, which are likely associated with an incommensurate charge order transition. The realization of two-dimensional topological insulators (2D TIs) in single-layer transition-metal dichalcogenide provides a promising platform for further exploration of the 2D TIs' physics and related applications.