Low-dimensional magnetism
e-mail: masuda@issp.u-tokyo.ac.jpLanguage in Speech : English
I will give a presentation on my work during my PhD focused on low-dimensional magnetism including “quasi-2-dimenison(2D)” and “synthetic 2D” materials. The quasi-2D is about van der Waals (vdW) magnets who are nearly 2 dimensional with negligible interlayer interaction due to the weak vdW coupling, for example, the Chromium trihalide CrCl3, and the Vanadium trihalide VI3. On the other hand, for the synthetic 2D system, I was focusing on the skyrmion hosting Pt/Co40Fe40B20/Ru-based multilayers for its depth dependent static and dynamical properties.
2D magnets have raised large interests due to the potential of being applied to spintronics devices and their magnetic subtleness. Among a vast variety of these materials, CrCl3 features an A-type antiferromagnetic order with easy-plane magnetic anisotropy, giving rise to an XY model and prediction on its ability to host merons [1], whereas the VI3 manifests a Kitaev-type exchange interaction [2] and a rich magnetic-structural phase diagram under. Due to the vdW nature, they exhibit high sensitivity to external pressure. Therefore, we have carried out both ambient and high-pressure experiments on them with muon spin rotation (μ+SR) [3, 4, 5], also neutron powder diffraction (NPD) was performed on CrCl3.
The Pt/Co40Fe40B20(CFB)/Ru-based multilayers have been a typical model system for realization of interfacial Dzyaloshinskii-Moriya interaction (DMI) [6] to stabilize Neel-type skyrmions. The heavy metal spacers inducing perpendicular anisotropy, DMI, and the interlayer exchange coupling between the CFB. Here, we used low energy μ+SR to study the magnetic fluctuations and revealed its 3 dimensionality beyond the toy-model of 2D point-like particles.
[1] Lu, Xiaobo, et al. Nat. Comm. 11.1 (2020): 4724.
[2] Gu, Yiqing, et al. Physical Review Letters 132.24 (2024): 246702.
[3] Forslund, Ola Kenji, et al. arXiv preprint arXiv:2111.06246 (2021).
[4] Ge, Yuqing, et al., in preparation.
[5] Forslund, Ola Kenji, et al. arXiv preprint arXiv:2210.17455 (2022).
[6] Moriya, Tôru. Physical review 120.1 (1960): 91.