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DOE OSTI · 2536829

Dimensionality crossover to a two-dimensional vestigial nematic state from a three-dimensional antiferromagnet in a honeycomb van der Waals magnet

Sun, Zeliang·Ye, Gaihua·Zhou, Chengkang·Huang, Mengqi·Huang, Nan·Xu, Xilong·Li, Qiuyang·Zheng, Guoxin·Ye, Zhipeng·Nnokwe, Cynthia·Li, Lu·Deng, Hui·Yang, Li·Mandrus, David·Meng, Zi Yang·Sun, Kai·Du, Chunhui Rita·He, Rui·Zhao, Liuyan
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Abstract

The effects of fluctuations and disorder, which are substantially enhanced in reduced dimensional-ities, can play a crucial role in producing nontrivial phases of matter such as vestigial orders char-acterized by a composite order parameter. However, fluctuation-driven magnetic phases in low dimensions have remained relatively unexplored. Here we demonstrate a phase transition from the zigzag antiferromagnetic order in the three-dimensional bulk to a Z 3 vestigial Potts-nematicity in two-dimensional few-layer samples of van der Waals magnet NiPS 3 . Our spin relaxometry and op-tical spectroscopy measurements reveal that the spin fluctuations are enhanced over the gigahertz to terahertz range as the layer number of NiPS 3 reduces. Monte Carlo simulations corroborate the experimental finding of 3-fold rotational symmetry breaking, but show that translational symmetry is restored in thin layers of NiPS 3 . Furthermore, our results show that strong quantum fluctuations can stabilize an unconventional magnetic phase after destroying a more conventional one.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICSMagnetic properties and materialsPhase transitions and critical phenomena

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Sun, Zeliang, Ye, Gaihua, Zhou, Chengkang, Huang, Mengqi, Huang, Nan, Xu, Xilong, Li, Qiuyang, Zheng, Guoxin, Ye, Zhipeng, Nnokwe, Cynthia, Li, Lu, Deng, Hui, Yang, Li, Mandrus, David, Meng, Zi Yang, Sun, Kai, Du, Chunhui Rita, He, Rui, Zhao, Liuyan. 2024-08-26. Dimensionality crossover to a two-dimensional vestigial nematic state from a three-dimensional antiferromagnet in a honeycomb van der Waals magnet. https://doi.org/10.1038/s41567-024-02618-6

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