Laser-induced Demagnetization in van der Waals $XY$- and Ising-like Antiferromagnets NiPS${}_3$ and FePS${}_3$

Abstract

The critical behaviour of laser-induced changes in magnetic ordering is studied experimentally in two-dimensional zigzag antiferromagnets $XY$-like NiPS${}_3$ and Ising-like FePS${}_3$. To examine laser-induced dynamics in flakes of these compounds, we employ time-resolved exchange linear dichroism effect sensitive to zigzag magnetic ordering and independent of the orientation of the antiferromagnetic vector. In both compounds laser excitation in the vicinity of the absorption edge induces partial quenching of the antiferromagnetic ordering manifested by exchange linear dichroism reduction. The amplitude of the effect varies with temperature as the derivative of the antiferromagnetic vector and exhibits a critical behaviour with the exponents corresponding to $XY$- and Ising-models for NiPS${}_3$ and FePS${}_3$, respectively. Critical slowing down of the demagnetization in the vicinity of Néel temperature is found, however, only in FePS${}_3$. In contrast, the increase of the demagnetization time near the ordering temperature in NiPS${}_3$ is minor. We show that the difference in the demagnetization times correlates well with the spin specific heat in both compounds. Beyond the range of slowing down, the demagnetization times in NiPS${}_3$ and FePS${}_3$ are comparable, about 5 - 10 ps, and are longer than those reported earlier for CoPS${}_3$ and considerably shorter than for MnPS${}_3$. This points to the importance of the unquenched angular momentum of transition-metal ions in laser-induced demagnetization process.

12 pages, 6 figures

References in corpus (13)

• Ising-Type Magnetic Ordering in Atomically Thin FePS3
• Suppression of magnetic ordering in XXZ-type antiferromagnetic monolayer NiPS3
• Optical determination of the Neel vector in a CuMnAs thin-film antiferromagnet
• Controlling the anisotropy of a van der Waals antiferromagnet with light
• The magnetic properties and structure of the quasi-two-dimensional antiferromagnet CoPS${}_3$
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• Controlling magnetism with light in a zero orbital angular momentum antiferromagnet
• Photo-induced magnetization enhancement in two-dimensional weakly anisotropic Heisenberg magnets

Cited by in corpus (3)

• Optical Spin Sensing and Metamagnetic Phase Control in the 2D Van der Waals Magnet Yb3+-Doped CrPS4
• Ultrafast Dynamics of Spin-Orbit Entangled Excitons Coupled to Magnetic Ordering in van der Waals Antiferromagnet NiPS3
• Coherent Spin-Phonon Coupling in the Layered Ferrimagnet Mn3Si2Te6