Magnetotransport signatures of Weyl physics and discrete scale invariance in the elemental semiconductor tellurium

Nan Zhang; Gan Zhao; Lin Li; Pengdong Wang; Lin Xie; Bin Cheng; Hui Li; Zhiyong Lin; Chuanying Xi; Jiezun Ke; Ming Yang; Jiaqing He; Zhe Sun; Zhengfei Wang; Zhenyu Zhang; Changgan Zeng

doi:10.1073/pnas.2002913117

Magnetotransport signatures of Weyl physics and discrete scale invariance in the elemental semiconductor tellurium

Proc Natl Acad Sci U S A. 2020 May 26;117(21):11337-11343. doi: 10.1073/pnas.2002913117. Epub 2020 May 12.

Authors

Nan Zhang^{1

2

3}, Gan Zhao^{1

2}, Lin Li^{4

2

3}, Pengdong Wang⁵, Lin Xie⁶, Bin Cheng^{1

2

3}, Hui Li⁷, Zhiyong Lin^{1

2

3}, Chuanying Xi⁸, Jiezun Ke⁹, Ming Yang⁹, Jiaqing He⁶, Zhe Sun⁵, Zhengfei Wang^{4

2}, Zhenyu Zhang^{1

2}, Changgan Zeng^{4

2

3}

Affiliations

¹ International Center for Quantum Design of Functional Materials, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, 230026 Hefei, Anhui, China.
² Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, 230026 Hefei, Anhui, China.
³ Chinese Academy of Sciences Key Laboratory of Strongly Coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, 230026 Hefei, Anhui, China.
⁴ International Center for Quantum Design of Functional Materials, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, 230026 Hefei, Anhui, China; lilin@ustc.edu.cn zfwang15@ustc.edu.cn cgzeng@ustc.edu.cn.
⁵ National Synchrotron Radiation Laboratory, University of Science and Technology of China, 230029 Hefei, Anhui, China.
⁶ Department of Physics, Southern University of Science and Technology, 518055 Shenzhen, China.
⁷ Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, Anhui, China.
⁸ High Magnetic Field Laboratory, Chinese Academy of Sciences, 230031 Hefei, Anhui, China.
⁹ Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China.

Abstract

The study of topological materials possessing nontrivial band structures enables exploitation of relativistic physics and development of a spectrum of intriguing physical phenomena. However, previous studies of Weyl physics have been limited exclusively to semimetals. Here, via systematic magnetotransport measurements, two representative topological transport signatures of Weyl physics, the negative longitudinal magnetoresistance and the planar Hall effect, are observed in the elemental semiconductor tellurium. More strikingly, logarithmically periodic oscillations in both the magnetoresistance and Hall data are revealed beyond the quantum limit and found to share similar characteristics with those observed in ZrTe₅ and HfTe₅ The log-periodic oscillations originate from the formation of two-body quasi-bound states formed between Weyl fermions and opposite charge centers, the energies of which constitute a geometric series that matches the general feature of discrete scale invariance (DSI). Our discovery reveals the topological nature of tellurium and further confirms the universality of DSI in topological materials. Moreover, introduction of Weyl physics into semiconductors to develop "Weyl semiconductors" provides an ideal platform for manipulating fundamental Weyl fermionic behaviors and for designing future topological devices.

Keywords: Weyl semiconductor; log-periodic oscillations; negative longitudinal magnetoresistance; planar Hall effect; tellurium.