Ultrafast Nonlinear Optical Spectroscopy of the Charge Density Wave in 1T-TaS2

ORAL

Abstract

Nonlinear optics has recently emerged as an appealing symmetry-sensitive probe for revealing and investigating exotic quantum phases of matter, in addition to its more traditional application in determining crystalline structures. Here, we report using temperature-dependent and time-resolved nonlinear optical techniques to study the 1T polytype of TaS2, an intensively-studied prototypical system hosting the charge density wave (CDW) order. We show that an enhancement of broken mirror symmetry is identified across the nearly commensurate to commensurate CDW transition by rotation anisotropy second harmonic generation (RA SHG). We then report the ultrafast responses of commensurate CDW to optical excitations, using both time-resolved reflectivity and time-resolved RA SHG. The excitation fluence dependence of the commensurate CDW phase will further be discussed.

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Presenters

  • Xiangpeng Luo

    • Peking University, China
    • Univ of Michigan - Ann Arbor

Authors

  • Xiangpeng Luo

    • Peking University, China
    • Univ of Michigan - Ann Arbor

  • Wencan Jin

    • Auburn University
    • University of Michigan
    • Univ of Michigan - Ann Arbor

  • Sang-Wook Cheong

    • Rutgers University
    • R-CEM & Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
    • Rutgers Center for Emergent Materials, Rutgers University
    • Department of Physics and Astronomy, Center for Emergent Materials, Rutgers University; Max Planck POSTECH/Korea Research Initiative, Pohang University of Science and Technol
    • Physics and Astronomy, Rutgers University
    • Rutgers University, Physics and Astronomy, and Laboratory for Pohang Emergent Materials and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
    • Rutgers University, Piscataway
    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics, Rutgers University
    • Physics & Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University
    • Rutgers University, New Brunswick
    • Physics, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA

  • Liuyan Zhao

    • Department of Physics, University of Michigan
    • Univ of Michigan - Ann Arbor
    • University of Michigan
    • University of Michigan - Ann Arbor