title: Dramatically decreased magnetoresistance in non-stoichiometric WTe2 crystals.
abstract: Recently, the layered semimetal WTe2 has attracted renewed interest owing to the observation of a non-saturating and giant positive magnetoresistance (~10(5)%), which can be useful for magnetic memory and spintronic devices. However, the underlying mechanisms of the giant magnetoresistance are still under hot debate. Herein, we grew the stoichiometric and non-stoichiometric WTe2 crystals to test the robustness of giant magnetoresistance. The stoichiometric WTe2 crystals have magnetoresistance as large as 3100% at 2 K and 9-Tesla magnetic field. However, only 71% and 13% magnetoresistance in the most non-stoichiometry (WTe1.80) and the highest Mo isovalent substitution samples (W0.7Mo0.3Te2) are observed, respectively. Analysis of the magnetic-field dependent magnetoresistance of non-stoichiometric WTe2 crystals substantiates that both the large electron-hole concentration asymmetry and decreased carrier mobility, induced by non-stoichiometry, synergistically lead to the decreased magnetoresistance. This work sheds more light on the origin of giant magnetoresistance observed in WTe2.
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Yang-Yang
authors.initials: YY
authors.lastname: Lv
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Pang
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Da-Jun
authors.initials: DJ
authors.lastname: Lin
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Shu-Hua
authors.initials: SH
authors.lastname: Yao
authors.affiliation: National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Y B
authors.initials: YB
authors.lastname: Chen
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Shan-Tao
authors.initials: ST
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Lu
authors.affiliation: School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.
authors.forename: Zhongkai
authors.initials: Z
authors.lastname: Liu
authors.affiliation: School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.|State Key Laboratory of Low Dimensional Quantum Physics, Collaborative Innovation Center of Quantum Matter and Department of Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Yan-Feng
authors.initials: YF
authors.lastname: Chen