报告人： 姚道新

单位： 中山大学物理科学与工程技术学院、光电材料与技术国家重点实验室
时间： 10月9号（周日）上午9:45
地点: 田家炳楼南205会议室

摘要： First I will give a brief introduction about the Iron-based
superconductors. I will then show how to estimate the exchange couplings
from neutron scattering data. I will talk about the two-orbital,
three-orbital and five-orbital models, compare results with neutron
scattering, ARPES, STM, etc. I will show how to use multiorbital models
to study the orbital-weight redistribution induced by spin order in the
iron pnictides. By comparing with the neutron-scattering and
angle-resolved photoemission experiments, we find the severe constraints
on the range of values for the intraorbital Hubbard repulsion U and Hund
coupling J in the mean-field approximation. We use a two-orbital Hubbard
model to study the charge and spin configurations in the pnictides. By
using the method of the real-space Hartree-Fock approximation on finite
clusters, we find that states with charge stripes are stabilized upon
electron doping. The observed charge stripes can be perpendicular or
parallel to the direction of the spin stripes of the undoped magnetic
ground state. When the undoped state has a Hubbard gap, the charge
striped states become robust. By introducing the quenched disorder, we
find the interesting electronic nematic states. In newly discovered iron
Se2, we use a five-orbital Hubbard model to studyxchalcogenides- AFe2−
the magnetic state. We find that the phase diagram contains an
insulating state with the same block spin pattern observed
experimentally, where the Fe-vacancies arranged in a $\sqrt{5}x\sqrt{5}$
pattern. The calculated magnetic moment is in good agreement with
experiments and a variety of other phases are also found in the phase
diagram.

简介：姚道新现为中山大学教授、博士生导师。1994年浙江大学物理系本科毕
业，1998年浙江大学理论物理硕士学位，期间在日本福井大学应用物 理系留学1
年。2007年在美国Boston University获得理学博士学位。2007年4月至2009年8月
在美国普渡大学做凝聚态物理博士后研究，2009年下半年在美国田纳西大学和橡树
岭国家实验室做博士后研究。2009年底起作为中山大学百人计划特聘教授工作。主
要研究方向为：铁基超导体的磁性、轨道、超导配对态等；铜氧高温 超导体和过
渡金属氧化物的自旋、电荷有序态；磁阻挫系统、量子相变和量子Monte Carlo；
拓扑绝缘体等关联电子体系的磁性问题。已发表多篇高质量的论文，包括Nature
Physics，PRL和PRB，获得很高的引用率。多次在国际学术会议和著名大学做学术
报告。目前担任Frontiers of Physics刊物2011年纪念超导百年专刊的Guest
Editor、经理助理、广东省物理学会理事等职务。