Stanford Advisors

Contact

  • Academic
    chenhang@stanford.edu
    University - Scholar Department: Physics Position: Postdoctoral Scholar

Additional Info

  • Mail Code: 4045

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All Publications

  • Structural Contribution to Light-Induced Gap Suppression in Ta_{2}NiSe_{5}. Physical review letters Chen, Z., Xu, C., Xie, C., Tang, W., Liu, Q., Wu, D., Xu, Q., Jiang, T., Zhu, P., Zou, X., Li, J., Wang, Z., Wang, N., Qian, D., Zong, A., Xiang, D. 2025; 135 (9): 096901

    Abstract

    An excitonic insulator is a material that hosts an exotic ground state, where an energy gap opens due to spontaneous condensation of bound electron-hole pairs. Ta_{2}NiSe_{5} is a promising candidate for this type of material, but the coexistence of a structural phase transition with the gap opening has led to a long-standing debate regarding the origin of the insulating gap. Here we employ MeV ultrafast electron diffraction to obtain quantitative insights into the atomic displacements in Ta_{2}NiSe_{5} following photoexcitation, which has been overlooked in previous time-resolved spectroscopy studies. In conjunction with first-principles calculations using the measured atomic displacements, we find that the structural change can largely account for the photoinduced reduction in the energy gap without considering excitonic effects. Our Letter illustrates the importance of a quantitative reconstruction of individual atomic pathways during nonequilibrium phase transitions, paving the way for a mechanistic understanding of a diverse array of phase transitions in correlated materials where lattice dynamics can play a pivotal role.

    View details for DOI 10.1103/1kzk-sz7g

    View details for PubMedID 40952197

  • Structural Contribution to Light-Induced Gap Suppression in Ta2NiSe5 PHYSICAL REVIEW LETTERS Chen, Z., Xu, C., Xie, C., Tang, W., Liu, Q., Wu, D., Xu, Q., Jiang, T., Zhu, P., Zou, X., Li, J., Wang, Z., Wang, N., Qian, D., Zong, A., Xiang, D. 2025; 135 (9)

    View details for DOI 10.1103/1kzk-sz7g

    View details for Web of Science ID 001563968300001

  • Time-domain study of coupled collective excitations in quantum materials NPJ QUANTUM MATERIALS Xu, C., Zong, A. 2025; 10 (1)

    View details for DOI 10.1038/s41535-025-00726-x

    View details for Web of Science ID 001421278900002