# Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate ${\mathrm{Mo}}_{x}{\mathrm{W}}_{1-x}{\mathrm{Te}}_{2}$

## Abstract

It has recently been proposed that electronic band structures in crystals can give rise to a previously overlooked type of Weyl fermion, which violates Lorentz invariance and, consequently, is forbidden in particle physics. It was further predicted that Mo _{x} W _{1 - x} Te _{2} may realize such a type-II Weyl fermion. Here, we first show theoretically that it is crucial to access the band structure above the Fermi level ε F to show a Weyl semimetal in Mo _{x} W _{1 - x} Te _{2} . Then, we study Mo x W _{1 - x} Te _{2} by pump-probe ARPES and we directly access the band structure > 0.2 eV above ε F in experiment. By comparing our results with ab initio calculations, we conclude that we directly observe the surface state containing the topological Fermi arc. We propose that a future study of Mo _{x} W _{1 - x} Te _{2} by pump-probe ARPES may directly pinpoint the Fermi arc. Our work sets the stage for the experimental discovery of the first type-II Weyl semimetal in Mo _{x} W _{1 - x} Te _{2} .

- Authors:
- more »

- Publication Date:

- Research Org.:
- Ames Laboratory (AMES), Ames, IA (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)

- OSTI Identifier:
- 1342950

- Report Number(s):
- IS-J 8989

Journal ID: ISSN 2469-9950; PRBMDO

- DOE Contract Number:
- FG-02-05ER46200; 26800165; AC02-07CH11358; 91421109; 11522432; 21571097; BK20130054; NRF-RF2013-08; NRF-NRFF2013-03; M4081137.070

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review B

- Additional Journal Information:
- Journal Volume: 94; Journal Issue: 8; Journal ID: ISSN 2469-9950

- Publisher:
- American Physical Society (APS)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

### Citation Formats

```
Belopolski, Ilya, Xu, Su-Yang, Ishida, Yukiaki, Pan, Xingchen, Yu, Peng, Sanchez, Daniel S., Zheng, Hao, Neupane, Madhab, Alidoust, Nasser, Chang, Guoqing, Chang, Tay-Rong, Wu, Yun, Bian, Guang, Huang, Shin-Ming, Lee, Chi-Cheng, Mou, Daixiang, Huang, Lunan, Song, You, Wang, Baigeng, Wang, Guanghou, Yeh, Yao-Wen, Yao, Nan, Rault, Julien E., Le Fèvre, Patrick, Bertran, François, Jeng, Horng-Tay, Kondo, Takeshi, Kaminski, Adam, Lin, Hsin, Liu, Zheng, Song, Fengqi, Shin, Shik, and Hasan, M. Zahid.
```*Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate MoxW1-xTe2*. United States: N. p., 2016.
Web. doi:10.1103/PhysRevB.94.085127.

```
Belopolski, Ilya, Xu, Su-Yang, Ishida, Yukiaki, Pan, Xingchen, Yu, Peng, Sanchez, Daniel S., Zheng, Hao, Neupane, Madhab, Alidoust, Nasser, Chang, Guoqing, Chang, Tay-Rong, Wu, Yun, Bian, Guang, Huang, Shin-Ming, Lee, Chi-Cheng, Mou, Daixiang, Huang, Lunan, Song, You, Wang, Baigeng, Wang, Guanghou, Yeh, Yao-Wen, Yao, Nan, Rault, Julien E., Le Fèvre, Patrick, Bertran, François, Jeng, Horng-Tay, Kondo, Takeshi, Kaminski, Adam, Lin, Hsin, Liu, Zheng, Song, Fengqi, Shin, Shik, & Hasan, M. Zahid.
```*Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate MoxW1-xTe2*. United States. doi:10.1103/PhysRevB.94.085127.

```
Belopolski, Ilya, Xu, Su-Yang, Ishida, Yukiaki, Pan, Xingchen, Yu, Peng, Sanchez, Daniel S., Zheng, Hao, Neupane, Madhab, Alidoust, Nasser, Chang, Guoqing, Chang, Tay-Rong, Wu, Yun, Bian, Guang, Huang, Shin-Ming, Lee, Chi-Cheng, Mou, Daixiang, Huang, Lunan, Song, You, Wang, Baigeng, Wang, Guanghou, Yeh, Yao-Wen, Yao, Nan, Rault, Julien E., Le Fèvre, Patrick, Bertran, François, Jeng, Horng-Tay, Kondo, Takeshi, Kaminski, Adam, Lin, Hsin, Liu, Zheng, Song, Fengqi, Shin, Shik, and Hasan, M. Zahid. Mon .
"Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate MoxW1-xTe2". United States. doi:10.1103/PhysRevB.94.085127.
```

```
@article{osti_1342950,
```

title = {Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate MoxW1-xTe2},

author = {Belopolski, Ilya and Xu, Su-Yang and Ishida, Yukiaki and Pan, Xingchen and Yu, Peng and Sanchez, Daniel S. and Zheng, Hao and Neupane, Madhab and Alidoust, Nasser and Chang, Guoqing and Chang, Tay-Rong and Wu, Yun and Bian, Guang and Huang, Shin-Ming and Lee, Chi-Cheng and Mou, Daixiang and Huang, Lunan and Song, You and Wang, Baigeng and Wang, Guanghou and Yeh, Yao-Wen and Yao, Nan and Rault, Julien E. and Le Fèvre, Patrick and Bertran, François and Jeng, Horng-Tay and Kondo, Takeshi and Kaminski, Adam and Lin, Hsin and Liu, Zheng and Song, Fengqi and Shin, Shik and Hasan, M. Zahid},

abstractNote = {It has recently been proposed that electronic band structures in crystals can give rise to a previously overlooked type of Weyl fermion, which violates Lorentz invariance and, consequently, is forbidden in particle physics. It was further predicted that Mo x W 1 - x Te 2 may realize such a type-II Weyl fermion. Here, we first show theoretically that it is crucial to access the band structure above the Fermi level ε F to show a Weyl semimetal in Mo x W 1 - x Te 2 . Then, we study Mo x W 1 - x Te 2 by pump-probe ARPES and we directly access the band structure > 0.2 eV above ε F in experiment. By comparing our results with ab initio calculations, we conclude that we directly observe the surface state containing the topological Fermi arc. We propose that a future study of Mo x W 1 - x Te 2 by pump-probe ARPES may directly pinpoint the Fermi arc. Our work sets the stage for the experimental discovery of the first type-II Weyl semimetal in Mo x W 1 - x Te 2 .},

doi = {10.1103/PhysRevB.94.085127},

journal = {Physical Review B},

issn = {2469-9950},

number = 8,

volume = 94,

place = {United States},

year = {2016},

month = {8}

}