本课题组围绕凝聚态物理理论前沿问题展开研究，已有成果的研究方向如下：
A. 二维材料的新奇电子性质
二维材料如石墨烯，过渡金属硫族化合物等展现出新奇的电子性质，如相对论性狄拉克电子激发，应变下生成赝磁场导致零场朗 道量子化。扭转的多层材料大幅调节电子能带结构，产生一系列新奇的物理，如平带，超导，(分数)量子反常霍尔效应等。
另外维度的降低导致介电屏蔽减弱，激子效应显著，决定材料光学性质。二维材料平台是研究激子物理的理想平台。
已有成果：
4. Qixing Wang, Yu Li Huang, Qi Zhang, Jiayu Ma, Xin Luo*, and Yun-Mei Li*, Self-energy corrections to zone-edge acoustic phonons in monolayer and bilayer WS2, Phys. Rev. B 109, L121202 (2024).
3. Qing-Hai Tan#, Yun-Mei Li#, Jia-Min Lai, Yu-Jia Sun, Zhe Zhang, Feilong Song, Cedric Robert, Xavier Marie, Weibo Gao, Ping-Heng Tan, and Jun Zhang, Quantum interference between dark-excitons and zone-edged acoustic phonons in few-layer WS2, Nature Communications 14, 88 (2023).
2. Yun-Mei Li, Xiaoying Zhou, Yan-Yang Zhang, Dong Zhang and Kai Chang, Dirac Fermions and Pseudo-magnetic Fields in Two-dimensional Electron Gases with Triangular Antidot Lattices, Physical Review B 96, 035406 (2017).
1. Yun-Mei Li, Jian Li, Li-Kun Shi, Dong Zhang, Wen Yang, and Kai Chang, Light-Induced Exciton Spin Hall Effect in van der Waals Heterostructures, Physical Review Letters 115, 166804 (2015).
B. 拓扑物态的研究
拓扑物理学以其独特的视角革新了人们对物质本质的理解，它打破了基于对称性对物质进行分类的传统，创新性地引入了拓扑不变量的概念，拓扑非平庸的体系展现出众多新奇的物理现象如体边对应关系，边缘态等。目前拓扑物态的研究是凝聚态物理的重要组成部分。
已有成果：
6. Yun-Mei Li, Bin Wei, and Kai Chang, Comment on “Topological Phase Transitions of Dirac Magnons in Honeycomb Ferromagnets”, Phys. Rev. Lett. 132, 219601 (2024).
5. Shasha Ke, Wen-Kai Lou*, Yun-Mei Li*, and Kai Chang*,Topological antichiral edge states and one-waybulk states in patterned ferromagnetic thin films, Applied Physics Letters 123, 242404 (2023).
4. Yun-Mei Li*, Antihelical edge magnons in patterned antiferromagnetic thin films, Physical Review Research 5, 033026 (2023).
3. Yun-Mei Li,* Xi-Wang Luo, and Kai Chang, Temperature-induced magnonic Chern insulator in collinear antiferromagnets, Physical Review B 107, 214417 (2023).
2. Yun-Mei Li*, Ya-Jie Wu, Xi-Wang Luo, Yongwei Huang, and Kai Chang, Higher-order topological phases of magnons protected by magnetic crystalline symmetries, Physical Review B 106, 054403 (2022).
1. Yun-Mei Li, Jiang Xiao and Kai Chang, Topological Magnon Modes in Patterned Ferrimagnetic Insulator Thin Films, Nano Letters 18, 3032 (2018).
C. 磁性系统中的物理研究
磁性物理是凝聚态物理长盛不衰的研究方向。磁性系统中的元激发称为自旋波或者磁子，自旋波可用作信息载体传输处理信息。前序研究工作结合拓扑与磁子对拓扑磁子进行了长久的研究,成果包含B中一部分。本课题组后续将关注磁性体系更多的物理现象。
已有成果：
1. Shasha Ke, Yun-Mei Li*, Wen-Kai Lou* and Kai Chang*, Pure magnon valley currents in a patterned ferromagnetic thin film, Physical Review B 107, 104426 (2023).