In this paper we present a comprehensive study on the multi-objective optimization of two-dimensional porous phononic crystals (PnCs) in both square and triangular lattices with the reduced topology symmetry of the unit-cell. The fast non-dominated sorting-based genetic algorithm II is used to perform the optimization, and the Pareto-optimal solutions are obtained. The results demonstrate that the symmetry reduction significantly influences the optimized structures. The physical mechanism of the optimized structures is analyzed. Topology optimization combined with the symmetry reduction can discover new structures and offer new degrees of freedom to design PnC-based devices. Especially, the rotationally symmetrical structures presented here can be utilized to explore and design new chiral metamaterials.
Thermoelectric Properties of Nanoscale three dimensional Si Phononic Crystal
研究了具有球形孔的n型纳米级三维Si声子晶体的热电性能。利用密度泛函理论和弛豫时间近似下的Boltzmann输运方程研究了电子输运系数、电导率、Seebeck系数和电子热导率。结果表明，在室温（300 K）下，3D Si PnC的电子输运系数与Si相比变化不大，电导率和热导率随载流子浓度的变化分别降低0.26 ~ 0.41和0.39 ~ 0.55，Seebeck系数与体Si相近.然而，具有球形孔的3D Si PnCs的晶格热导率通过分子动力学方法计算降低了500倍，导致ZT为0.76，这是多孔Si的约30倍。这项工作表明，3D Si PnC是一个有前途的候选人，高效率的热电材料。
Ionic liquids under confinement: From systematic variations of the ion and pore sizes towards an understanding of structure and dynamics in complex porous carbons
Interaction Topological Transformer for Multiscale Learning in Porous Materials
Department of Mathematics, Michigan State University（数学系，密歇根州立大学）；Physical Sciences Division, Pacific Northwest National Laboratory（物理科学部，太平洋西北国家实验室）；Department of Electrical and Computer Engineering, Michigan State University（电气与计算机工程系，密歇根州立大学）；Department of Biochemistry and Molecular Biology, Michigan State University（生物化学与分子生物学系，密歇根州立大学）
Symmetry-Protected Phonon Topology and Low Lattice Thermal Conductivity in Square-Octagonal Chalcogenides
Khalifa University（哈利法大学）；Seoul National University（首尔国立大学）；Indian Institute of Technology, Bombay（印度理工学院孟买分校）；Research and Innovation Center for Graphene and 2D materials (RIC2D)（石墨烯与二维材料研究与创新中心）
Superconductivity and Band Topology in Functionalized 2D Hexagonal MBenes
University of Tehran（德黑兰大学）；Binghamton University-SUNY（宾汉姆顿大学-纽约州立大学）；JAIST（石川金泽工业大学）；Institute of Science Tokyo（东京科学大学）；Institute for Research in Fundamental Sciences (IPM)（伊朗基础科学研究所）
