title: Pressure-Induced New Topological Weyl Semimetal Phase in TaAs.
abstract: We report a new pressure-induced phase in TaAs with different Weyl fermions than the ambient structure with the aid of theoretical calculations, experimental transport and synchrotron structure investigations up to 53 GPa. We show that TaAs transforms from an ambient I4_{1}md phase (t-TaAs) to a high-pressure hexagonal P-6m2  (h-TaAs) phase at 14 GPa, along with changes of the electronic state from containing 24 Weyl nodes distributed at two energy levels to possessing 12 Weyl nodes at an isoenergy level, which substantially reduces the interference between the surface and bulk states. The new pressure-induced phase can be reserved upon releasing pressure to ambient condition, which allows one to study the exotic behavior of a single set of Weyl fermions, such as the interplay between surface states and other properties.
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.|Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Pengchao
authors.initials: P
authors.lastname: Lu
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Du
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Xiangde
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, China.
authors.forename: Ganghua
authors.initials: G
authors.lastname: Zhang
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Ranran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Dexi
authors.initials: D
authors.lastname: Shao
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.|Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Xuliang
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Wang
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Tian
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Xiangang
authors.initials: X
authors.lastname: Wan
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.|Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Zhaorong
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, China.|High Pressure Synergetic Consortium (HPSynC), Geophysical Laboratory, Carnegie Institution of Washington, 9700S Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Wenge
authors.initials: W
authors.lastname: Yang
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Yuheng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Dingyu
authors.initials: D
authors.lastname: Xing