title: A metallic mosaic phase and the origin of Mott-insulating state in 1T-TaS2.
abstract: Electron-electron and electron-phonon interactions are two major driving forces that stabilize various charge-ordered phases of matter. In layered compound 1T-TaS2, the intricate interplay between the two generates a Mott-insulating ground state with a peculiar charge-density-wave (CDW) order. The delicate balance also makes it possible to use external perturbations to create and manipulate novel phases in this material. Here, we study a mosaic CDW phase induced by voltage pulses, and find that the new phase exhibits electronic structures entirely different from that of the original Mott ground state. The mosaic phase consists of nanometre-sized domains characterized by well-defined phase shifts of the CDW order parameter in the topmost layer, and by altered stacking relative to the layers underneath. We discover that the nature of the new phase is dictated by the stacking order, and our results shed fresh light on the origin of the Mott phase in 1T-TaS2.
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Liguo
authors.initials: L
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Cun
authors.initials: C
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.|Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Xiu Fang
authors.initials: XF
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Niu
authors.affiliation: Korea Institute for Advanced Study, Hoegiro 85, Seoul 02455, Korea.
authors.forename: Sejoong
authors.initials: S
authors.lastname: Kim
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Donglai
authors.initials: D
authors.lastname: Feng
authors.affiliation: Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: David
authors.initials: D
authors.lastname: Tománek
authors.affiliation: Korea Institute for Advanced Study, Hoegiro 85, Seoul 02455, Korea.
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Son
authors.affiliation: Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.|Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Xian Hui
authors.initials: XH
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D004581:Electronics; D004583:Electrons; D044367:Phase Transition; D060739:Phonons; D013440:Sulfides / Q000737:chemistry*; D013635:Tantalum / Q000737:chemistry*; D013696:Temperature
chemical_list: D013440:Sulfides; D013635:Tantalum