题目:Relativistic Fermions Generated by Square Lattices in Layered Compounds
报告人:Zhiqiang Mao Tulane University
地点: 教十二-201
时间: 6月20日,周二,10:30-11:30
摘要:
Recent discoveries of topological semimetals have generated immense interests since they represent new topological states of quantum matters. In this talk, I will present our recent studies on topological semimetals [1-4], which are focused on Dirac/Weyl fermions generated by square lattices in layered compounds. I will first report on our discoveries of two new magnetic Dirac materials Sr1-yMn1-zSb2 [1] and BaMnSb2 [2] in which nearly massless Dirac fermions are generated by 2D Sb layers. In Sr1-yMn1-zSb2, Dirac fermions are found to coexist with ferromagnetism, offering a rare opportunity to investigate the interplay between relativistic fermions and spontaneous time reversal symmetry breaking and explore a possible magnetic Weyl state. Then I will show our quantum oscillation studies on two new Dirac nodal line semimetals – ZrSiSe and ZrSiTe [3]. We have not only revealed their signatures of nodal-line fermions, but also demonstrated that their atomically thin crystals are accessible via mechanical exfoliation, raising the possibility of realizing the theoretically predicted 2D topological insulators [5]. Finally I will discuss exotic quantum transport behavior arising from the zeroth Landau level in Weyl semimetal YbMnBi2 [4,6].
References:
[1] Liu et al., arXiv:1507.07978, to appear in Nature Materials.
[2] Liu et al., Sci. Rep. 6, 30525 (16).
[3] Hu et al., PRL 117, 016602 (16).
[4] Liu et al., arXiv: 1608.05956
[5] Q. Xu et al., PRB 92, 205310 (15).
[6] Borisenko et al., arXiv: 1507.04847 (12).
个人简介:
Zhiqiang Mao is Professor of the Department of Physics and Engineering Physics at Tulane University. He also hold Nicholas J. Altiero professorship in Science and Engineering.
Mao received his Ph. D degree in Physics from University of Science and Technology of China in 1992. After his postdoc training at Kyoto University in Japan and Pennsylvania State University, he was recruited as an assistant professor in 2002 to Tulane University, where he rose to the rank of Professor in Physics in 2009.
Mao’s research interest is quantum materials, including strongly correlated oxides, 2D materials, unconventional superconductors and topological materials. He has published over 280 peer-reviewed papers, with the total citation counts about9500 and the citation H-index of 46 (Google Scholar). Hehas also been honored with severalawards, includingthe Tulane University School of Science and Engineering Outstanding Researcher Award (2017), the NSF Career Award (2007), the Cottrell Scholar Award (2005). He was elected Fellow of the American Physical Society in 2015 for contributions to the understanding of magnetism and superconductivity in iron-based superconductors and correlated electron states in ruthenates.
欢迎老师和同学参加!