刘锋
美国犹他大学材料科学与工程系教授、系主任
时间: 5月29日（星期四）下午2:30
地点: 唐仲英楼B501
摘要：
Topological insulators (TIs) are a recently discovered class of materials having insulating bulk electronic states but conducting boundary states distinguished by nontrivial topology. So far, several generations of TIs have been theoretically predicted and experimentally confirmed, all based on inorganic materials. In this talk, I will present our recent study of a family of two-dimensional organic TIs made of organometallic lattices [1-4], based on first-principles calculations and tight-binding model analyses. Designed by assembling molecular building blocks of organometallic compounds with strong spin-orbit coupling into a hexagonal and Kagome lattices, these new classes of organic topological materials are shown to exhibit nontrivial topological edge states in both Dirac bands [1,4] and flat Chen bands (so-called fractional Chern insulator) [2,4], which are robust against significant lattice strain. Realization of half metallic state and anomalous quantum Hall effect in magnetic organic TIs with the inclusion of transition metal elements will also be discussed [3]. We envision that organic topological materials will greatly broaden the scientific scope and technological impact of emerging topological materials.
[1] Z. F. Wang, Zheng Liu and Feng Liu, “Organic topological insulators in organometallic lattices”, Nature Commun. 4, 1471 (2013).
[2] Z. Liu, Z. F. Wang, J.-W. Mei, Y. Wu and Feng Liu, “Flat Chern Band in a Two-Dimensional Organometallic Framework”, Phys. Rev. Lett. 110, 106804 (2013).
[3] Z. F. Wang, Z. Liu and Feng Liu, “Quantum anomalous Hall effect in 2D organic topological insulator”, Phys. Rev. Lett. 110, 196801 (2013).
[4] Z. F. Wang, N. Su and Feng Liu, “Prediction of a Two-Dimensional Organic Topological Insulator”, Nano Letters, 13, 2842 (2013).
刘锋，犹他大学材料科学与工程系终身教授、系主任。2008年获得Senior Humboldt Award，2011年当选美国物理学会会士，2012年入选“千人计划B类”清华大学访问教授. 刘锋教授的主要研究领域是纳米材料，纳米器件和计算物理。近年来，他在这些领域做出了多项世界公认的领先工作。是应变引导的纳米结构自主装和纳米力学构筑 (Nanomechanical Architecture) 领域的开拓者之一。首次提出有机拓扑绝缘体。刘锋教授已发表近200多篇学术论文（50 多篇PRL，两篇Nature及十几篇其他高影响因子刊物），拥有10多项专利，8章丛书和16篇特邀综述论文，在世界各地作过近200场学术邀请报告。