Above-room-temperature chiral skyrmion lattice and Dzyaloshinskii-Moriya interaction in a van der Waals ferromagnet Fe3-xGaTe2

Chenhui Zhang; Ze Jiang; Jiawei Jiang; Wa He; Junwei Zhang; Fanrui Hu; Shishun Zhao; Dongsheng Yang; Yakun Liu; Yong Peng; Hongxin Yang; Hyunsoo Yang

doi:10.1038/s41467-024-48799-9

Above-room-temperature chiral skyrmion lattice and Dzyaloshinskii-Moriya interaction in a van der Waals ferromagnet Fe_3-xGaTe₂

Nat Commun. 2024 May 25;15(1):4472. doi: 10.1038/s41467-024-48799-9.

Authors

Chenhui Zhang^#¹, Ze Jiang^#², Jiawei Jiang^#³, Wa He², Junwei Zhang², Fanrui Hu¹, Shishun Zhao¹, Dongsheng Yang¹, Yakun Liu¹, Yong Peng⁴, Hongxin Yang^{5

6}, Hyunsoo Yang⁷

Affiliations

¹ Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore.
² School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China.
³ National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
⁴ School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China. [email protected].
⁵ National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China. [email protected].
⁶ Center for Quantum Matter, School of Physics, Zhejiang University, Hangzhou, 310058, China. [email protected].
⁷ Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore. [email protected].

^# Contributed equally.

Abstract

Skyrmions in existing 2D van der Waals (vdW) materials have primarily been limited to cryogenic temperatures, and the underlying physical mechanism of the Dzyaloshinskii-Moriya interaction (DMI), a crucial ingredient for stabilizing chiral skyrmions, remains inadequately explored. Here, we report the observation of Néel-type skyrmions in a vdW ferromagnet Fe_3-xGaTe₂ above room temperature. Contrary to previous assumptions of centrosymmetry in Fe_3-xGaTe₂, the atomic-resolution scanning transmission electron microscopy reveals that the off-centered Fe_ΙΙ atoms break the spatial inversion symmetry, rendering it a polar metal. First-principles calculations further elucidate that the DMI primarily stems from the Te sublayers through the Fert-Lévy mechanism. Remarkably, the chiral skyrmion lattice in Fe_3-xGaTe₂ can persist up to 330 K at zero magnetic field, demonstrating superior thermal stability compared to other known skyrmion vdW magnets. This work provides valuable insights into skyrmionics and presents promising prospects for 2D material-based skyrmion devices operating beyond room temperature.

Abstract

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