Pedramrazi Zahra, Herbig Charlotte, Pulkin Artem, Tang Shujie, Phillips Madeleine, Wong Dillon, Ryu Hyejin, Pizzochero Michele, Chen Yi, Wang Feng, Mele Eugene J, Shen Zhi-Xun, Mo Sung-Kwan, Yazyev Oleg V, Crommie Michael F
Department of Physics , University of California at Berkeley , Berkeley , California 94720 , United States.
Institute of Physics , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland.
Nano Lett. 2019 Aug 14;19(8):5634-5639. doi: 10.1021/acs.nanolett.9b02157. Epub 2019 Jul 29.
We report the creation and manipulation of structural phase boundaries in the single-layer quantum spin Hall insulator 1T'WSe by means of scanning tunneling microscope tip pulses. We observe the formation of one-dimensional interfaces between topologically nontrivial 1T' domains having different rotational orientations, as well as induced interfaces between topologically nontrivial 1T' and topologically trivial 1H phases. Scanning tunneling spectroscopy measurements show that 1T'/1T' interface states are localized at domain boundaries, consistent with theoretically predicted unprotected interface modes that form dispersive bands in and around the energy gap of this quantum spin Hall insulator. We observe a qualitative difference in the experimental spectral line shape between topologically "unprotected" states at 1T'/1T' domain boundaries and protected states at 1T'/1H and 1T'/vacuum boundaries in single-layer WSe.
我们报告了通过扫描隧道显微镜尖端脉冲在单层量子自旋霍尔绝缘体1T'WSe中创建和操纵结构相边界的过程。我们观察到具有不同旋转取向的拓扑非平凡1T'域之间形成了一维界面，以及拓扑非平凡1T'与拓扑平凡1H相之间的诱导界面。扫描隧道谱测量表明，1T'/1T'界面态定域在畴边界处，这与理论预测的未受保护的界面模式一致，该模式在这种量子自旋霍尔绝缘体的能隙内及周围形成色散带。我们观察到单层WSe中1T'/1T'畴边界处的拓扑“未受保护”态与1T'/1H和1T'/真空边界处的受保护态之间实验光谱线形状存在定性差异。
