报告题目：Plethora of Physics in a Kagome Ferromagnet: Weyl Nodes, Flat Bands, and Anomalous Fractionalized Charge
主讲人：Yona Soh 保罗谢尔研究所 研究员
时 间：2024年11月14日14:30
地 点：安徽大学磬苑校区理工E楼E400
主办单位：物理与光电工程学院
欢迎各位老师、同学届时前往！
报告摘要：
The kagome lattice is a particularly simple venue for seeing classical and quantum effects of frustration. Theoretical approaches have yielded many interesting conjectures (including for example the possibilities of quantum spin liquids and a fractional quantum Hall effect at zero applied field for ferromagnets), but experiments on real materials containing kagome layers have not validated even relatively straightforward predictions, such as flat bands, especially for metals. This follows because of the three-dimensionality and large unit cells of the materials. I will report on recent progress exploiting both density functional theory1, transport measurements2-4, and spectroscopic tools5,6 towards identifying Weyl nodes, flat bands, and anomalous fractionalized charge in a kagome ferromagnet, Fe3Sn2, which undergoes a spin reorientation transition that we visualize using magnetic force microscopy7.
References
1.Yao, M. et al. Switchable Weyl nodes in topological Kagome ferromagnet Fe3Sn2. arXiv preprint arXiv:1810.01514 (2018).
2.Kumar, N., Soh, Y., Wang, Y. H. & Xiong, Y. Magnetotransport as a diagnostic of spin reorientation: Kagome ferromagnet as a case study. Physical Review B 100, 7 (2019). https://doi.org/10.1103/PhysRevB.100.214420
3.Kumar, N., Soh, Y., Wang, Y., Li, J. & Xiong, Y. Anomalous planar Hall effect in a kagome ferromagnet. arXiv preprint arXiv:2005.14237 (2020).
4.Kumar, N., Soh, Y., Wang, Y., Li, J. & Y., X. Tuning the electronic band structure in a kagome ferromagnetic metal via magnetization. Phys Rev B 106, 045120 (2022).
5.Ekahana, S. A. et al. Anomalous electrons in a metallic kagome ferromagnet. Nature 627, 19 (2024). https://doi.org/10.1038/s41586-024-07085-w
6.Zhang, W. et al. Spin waves and orbital contribution to ferromagnetism in a topological metal. Nature Communications 15, 8905 (2024).
7.Heritage, K. et al. Images of a First‐Order Spin‐Reorientation Phase Transition in a Metallic Kagome Ferromagnet. Advanced Functional Materials 30 (2020). https://doi.org/10.1002/adfm.201909163
报告人简介：
Yona Soh，保罗谢尔研究所研究员。博士毕业于康奈尔大学应用物理学。曾凝聚态物理学家，执教于达特茅斯学院与帝国理工学院。研究方向聚焦低维系统、受挫磁体及磁性拓扑材料等关联体系的电磁特性。综合运用实验室先进设备与大型科研设施，深入探索这些复杂系统的物理本质。