Visualizing Type-II Weyl Points in Tungsten Ditelluride by Quasiparticle Interference

Chun-Liang Lin; Ryuichi Arafune; Ro Ya Liu; Masato Yoshimura; Baojie Feng; Kazuaki Kawahara; Zeyuan Ni; Emi Minamitani; Satoshi Watanabe; Youguo Shi; Maki Kawai; Tai Chang Chiang; Iwao Matsuda; Noriaki Takagi

doi:10.1021/acsnano.7b06179

Visualizing Type-II Weyl Points in Tungsten Ditelluride by Quasiparticle Interference

Chun-Liang Lin, Ryuichi Arafune, Ro Ya Liu, Masato Yoshimura, Baojie Feng, Kazuaki Kawahara, Zeyuan Ni, Emi Minamitani, Satoshi Watanabe, Youguo Shi, Maki Kawai, Tai Chang Chiang, Iwao Matsuda, Noriaki Takagi^*

^*Corresponding author for this work

Department of Electrophysics

Research output: Contribution to journal › Article › peer-review

39 Scopus citations

Abstract

Weyl semimetals (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 (WTe₂) has garnered a great deal of attention as a strong candidate to be a type-II WSM. However, the Weyl points for WTe₂ are located above the Fermi level, which has prevented us from identifying the locations and the connection to the Fermi arc surface states by using angle-resolved photoemission spectroscopy. Here, we present experimental proof that WTe₂ is a type-II WSM. We measured energy-dependent quasiparticle interference patterns with a cryogenic scanning tunneling microscope, revealing the position of the Weyl point and its connection with the Fermi arc surface states, in agreement with prior theoretical predictions. Our results provide an answer to this crucial question and stimulate further exploration of the characteristics of WSMs.

Original language	English
Pages (from-to)	11459-11465
Number of pages	7
Journal	ACS Nano
Volume	11
Issue number	11
DOIs	https://doi.org/10.1021/acsnano.7b06179
State	Published - 28 Nov 2017

Keywords

Fermi arc
WTe
Weyl semimetals
quasiparticle interference
scanning tunneling microscopy
topological matter
transition metal dichalcogenides

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10.1021/acsnano.7b06179

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@article{8863c6fa91f7437eaecfe91434ae22fe,

title = "Visualizing Type-II Weyl Points in Tungsten Ditelluride by Quasiparticle Interference",

abstract = "Weyl semimetals (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 (WTe2) has garnered a great deal of attention as a strong candidate to be a type-II WSM. However, the Weyl points for WTe2 are located above the Fermi level, which has prevented us from identifying the locations and the connection to the Fermi arc surface states by using angle-resolved photoemission spectroscopy. Here, we present experimental proof that WTe2 is a type-II WSM. We measured energy-dependent quasiparticle interference patterns with a cryogenic scanning tunneling microscope, revealing the position of the Weyl point and its connection with the Fermi arc surface states, in agreement with prior theoretical predictions. Our results provide an answer to this crucial question and stimulate further exploration of the characteristics of WSMs.",

keywords = "Fermi arc, WTe, Weyl semimetals, quasiparticle interference, scanning tunneling microscopy, topological matter, transition metal dichalcogenides",

author = "Chun-Liang Lin and Ryuichi Arafune and Liu, {Ro Ya} and Masato Yoshimura and Baojie Feng and Kazuaki Kawahara and Zeyuan Ni and Emi Minamitani and Satoshi Watanabe and Youguo Shi and Maki Kawai and Chiang, {Tai Chang} and Iwao Matsuda and Noriaki Takagi",

note = "Publisher Copyright: {\textcopyright} 2017 American Chemical Society.",

year = "2017",

month = nov,

day = "28",

doi = "10.1021/acsnano.7b06179",

language = "English",

volume = "11",

pages = "11459--11465",

journal = "ACS Nano",

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TY - JOUR

T1 - Visualizing Type-II Weyl Points in Tungsten Ditelluride by Quasiparticle Interference

AU - Lin, Chun-Liang

AU - Arafune, Ryuichi

AU - Liu, Ro Ya

AU - Yoshimura, Masato

AU - Feng, Baojie

AU - Kawahara, Kazuaki

AU - Ni, Zeyuan

AU - Minamitani, Emi

AU - Watanabe, Satoshi

AU - Shi, Youguo

AU - Kawai, Maki

AU - Chiang, Tai Chang

AU - Matsuda, Iwao

AU - Takagi, Noriaki

PY - 2017/11/28

Y1 - 2017/11/28

N2 - Weyl semimetals (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 (WTe2) has garnered a great deal of attention as a strong candidate to be a type-II WSM. However, the Weyl points for WTe2 are located above the Fermi level, which has prevented us from identifying the locations and the connection to the Fermi arc surface states by using angle-resolved photoemission spectroscopy. Here, we present experimental proof that WTe2 is a type-II WSM. We measured energy-dependent quasiparticle interference patterns with a cryogenic scanning tunneling microscope, revealing the position of the Weyl point and its connection with the Fermi arc surface states, in agreement with prior theoretical predictions. Our results provide an answer to this crucial question and stimulate further exploration of the characteristics of WSMs.

AB - Weyl semimetals (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 (WTe2) has garnered a great deal of attention as a strong candidate to be a type-II WSM. However, the Weyl points for WTe2 are located above the Fermi level, which has prevented us from identifying the locations and the connection to the Fermi arc surface states by using angle-resolved photoemission spectroscopy. Here, we present experimental proof that WTe2 is a type-II WSM. We measured energy-dependent quasiparticle interference patterns with a cryogenic scanning tunneling microscope, revealing the position of the Weyl point and its connection with the Fermi arc surface states, in agreement with prior theoretical predictions. Our results provide an answer to this crucial question and stimulate further exploration of the characteristics of WSMs.

KW - Fermi arc

KW - WTe

KW - Weyl semimetals

KW - quasiparticle interference

KW - scanning tunneling microscopy

KW - topological matter

KW - transition metal dichalcogenides

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U2 - 10.1021/acsnano.7b06179

DO - 10.1021/acsnano.7b06179

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AN - SCOPUS:85035767372

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VL - 11

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EP - 11465

JO - ACS Nano

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ER -

Visualizing Type-II Weyl Points in Tungsten Ditelluride by Quasiparticle Interference

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