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106-2專題演講-1070502
演講活動
張貼人：李明芳 ╱ 公告日期：2018-02-12|
Time：2018/5/2 (Wed.) 14:20~16:20
Speaker：Prof.林俊良(Chun-Liang Lin)
日本東京大學大學院新領域創成科學科/Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo
Title：Visualizing Type-II Weyl Points on WTe2 and MoTe2 Surfaces
Abstract：Topology in abstract mathematics has revolutionized our conventional understanding of condensed matter physics, resulting in the emergence of exotic quantum phases such as topological insulators (TIs). Recently the realization of the Weyl semimetals (WSMs) leads us to uncover the topological phases of matter beyond TIs. WSMs have gathered a deal of great attention because the quasiparticles in WSMs behave as Weyl fermions, massless chiral fermions long sought in particle physics. WSMs are classified into two types, type I and II, according to the topology of the Weyl point, where the electron and hole pockets touch each other. Tungsten Ditelluride (WTe 2 ) and Molibuden Ditelluride (MoTe 2 ) are strong candidates of type-II WSMs proposed by the theory. Here, we measured energy-dependent quasiparticle interference patterns on both T d phase WTe 2 and MoTe 2 with a cryogenic scanning tunneling microscope, revealing the position of the Weyl points and their connection with the Fermi arc surface states. The results as shown in Fig. 1 are also in agreement with prior theoretical predictions. Our results provide a conclusive answer to the issue and serve to motivate further exploration of the novel characteristics of WSMs [1, 2].
[1] C. –L. Lin et al. ACS Nano 11 11459 (2017)
[2] C. –L. Lin et al. J. Phys.: Condens. Matter 30 105703 (2018)
Place：Room S101, Gongquan Campuses, NTNU
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最後修改時間：2018-03-03 PM 3:50
