Emergence of 2D-XY antiferromagnetism in monolayer NiPS<sub>3</sub>

ORAL

Abstract

The realization of stable magnetic orderings in two-dimensional (2D) crystals beyond the Mermin-Wagner theorem offers a unique lens into the rich physics inherent to reduced dimensionality. Though the stabilization of 2D magnetic order with out-of-plane anisotropy has been unveiled in many 2D van der Waals systems, the demonstration of a 2D magnet susceptible to other types of persistent symmetry breaking has long been sought but has remained elusive. Here, we combine advanced optical techniques to unravel signatures of a Berezinskii–Kosterlitz–Thouless transition in NiPS3 and track its instability towards an antiferromagnetic long-range-ordered state. Analysis of the critical scaling of the order parameter reveals excellent agreement with the 2D XY universality class below the critical temperature. These results are interpreted via a six-clock model and supported by theoretical simulations. Our findings shed light on the intricate interplay between topology and symmetry breaking in two dimensions and establish a protocol to discover novel magnetic textures for spintronics.

*The work was supported by the Robert A. Welch Foundation (Grant, F-2092-20220331). This research was partially supported by the National Science Foundation through the Center for Dynamics and Control of Materials: an NSF MRSEC under Cooperative Agreement No. DMR-1720595 and DMR-2308817. These experiments were performed at the user facility supported by the National Science Foundation through the Center for Dynamics and Control of Material under Cooperative Agreement No. DMR-1720595 and DMR-2308817 and the Major Research Instrumentation (MRI) program DMR-2019130.

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Presenters

  • Frank Y Gao

    • University of Texas at Austin

Authors

  • Frank Y Gao

    • University of Texas at Austin

  • Dong Seob Kim

    • The University of Texas at Austin
    • University of Texas at Austin

  • Ajesh Kumar

    • Massachusetts Institute of Technology
    • University of Texas at Austin

  • Chao Lei

    • University of Texas at Austin

  • Xinyue Peng

    • The University of Texas at Austin

  • David Lujan

    • University of Texas at Austin

  • Jeongheon Choe

    • Columbia University
    • The University of Texas at Austin

  • Saba Arash

    • The University of Texas at Austin

  • Shivani Sharma

    • Academia Sinica

  • Raju Kalaivanan

    • Institute of Physics, Academia Sinica
    • Academia Sinica

  • Raman Sankar

    • Academia Sinica
    • Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan

  • Shangfan Lee

    • Academia Sinica
    • Inst of Physics Academia Sinica
    • Institute of Physics, Academia Sinica

  • Mengxing Ye

    • University of Utah

  • Allan H MacDonald

    • University of Texas at Austin

  • Xiaoqin Elaine Li

    • University of Texas at Austin
    • The University of Texas at Austin

  • Edoardo Baldini

    • The University of Texas at Austin