Origin of extremely large magnetoresistance in the candidate type-II Weyl semimetal MoTe2-x
- 주제(기타) Multidisciplinary Sciences
- 설명문(일반) [Lee, Sangyun; Kim, Sung-Il; Jung, Soon-Gil; Kim, Jihyun; Park, Kee-Su; Park, Tuson] Sungkyunkwan Univ, CQMS, Suwon 16419, South Korea; [Lee, Sangyun; Jang, Jaekyung; Kim, Sung-Il; Jung, Soon-Gil; Kim, Jihyun; Rhee, Joo Yull; Park, Kee-Su; Park, Tuson] Sungkyunkwan Univ, Dept Phys, Suwon 16419, South Korea; [Cho, Suyeon] Sungkyunkwan Univ, Ctr Integrated Nanostruct Phys CINAP, IBS, Suwon 16419, South Korea; [Cho, Suyeon] Ewha Womans Univ, Div Chem Engn & Mat Sci, Seoul 03760, South Korea; [Kim, Sung Wng] Sungkyunkwan Univ, Dept Energy Sci, Suwon 16419, South Korea
- 관리정보기술 faculty
- 등재 SCIE, SCOPUS
- 발행기관 NATURE PUBLISHING GROUP
- 발행년도 2018
- URI http://www.dcollection.net/handler/ewha/000000156897
- 본문언어 영어
- Published As http://dx.doi.org/10.1038/s41598-018-32387-1
초록/요약
The recent observation of extremely large magnetoresistance (MR) in the transition-metal dichalcogenide MoTe2 has attracted considerable interest due to its potential technological applications as well as its relationship with novel electronic states predicted for a candidate type-II Weyl semimetal. In order to understand the origin of the MR, the electronic structure of MoTe2-x (x = 0.08) is systematically tuned by application of pressure and probed via its Hall and longitudinal conductivities. With increasing pressure, a monoclinic-to-orthorhombic (1T' to T-d) structural phase transition temperature (T*) gradually decreases from 210 K at 1 bar to 58 K at 1.1 GPa, and there is no anomaly associated with the phase transition at 1.4 GPa, indicating that a T = 0 K quantum phase transition occurs at a critical pressure (P-c) between 1.1 and 1.4 GPa. The large MR observed at 1 bar is suppressed with increasing pressure and is almost saturated at 100% for P > P-c. The dependence on magnetic field of the Hall and longitudinal conductivities of MoTe2-x shows that a pair of electron and hole bands are important in the low-pressure T-d phase, while another pair of electron and hole bands are additionally required in the high-pressure 1T' phase. The MR peaks at a characteristic hole-to-electron concentration ratio (n(c)) and is sharply suppressed when the ratio deviates from n(c) within the T-d phase. These results establish the comprehensive temperature-pressure phase diagram of MoTe2-x and underscore that its MR originates from balanced electron-hole carrier concentrations.
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