报告人简介：
南京大学本科、硕士、博士研究生毕业，获博士学位，现为南京大学物理系教授，其中2003-2007，先后在日本国立材料研究所和美国加州大学戴维斯分校访问合作研究。主要采用第一性原理和有效模型相结合的手段研究具有强自旋轨道耦合的关联电子体系。因在烧绿石结构Ir氧化物中预言新奇Weyl半金属态的理论工作及相关第一性原理电子结构计算物理研究而获得2014年度香港大学Daniel Tsui(崔琦)Fellowship。2015年，获得国家杰出青年科学基金。2016年，获长江学者特聘教授。

报告摘要:
The same as Weyl and Majorana fermions, the relativistic spin-3/2 elementary particle, known as Rarita-Schwinger (RS) fermion, has also been proposed but not observed in the laboratory or nature. It is described by a vector-spinor field ψ_{μα}, whose number of components is larger than its independent degrees of freedom (DOF). Thus sharply in contrast with any wave equation describing spin-1/2 fermions, the RS equations contain nontrivial constraints to eliminate the redundant DOF. Consequently the standard procedure adopted in realizing relativistic spin-1/2 quasi-particle is not capable of creating the RS fermion in condensed matter systems (CMS). In this work, we propose a generic method to construct a Hamiltonian which implicitly contains the RS constraints, thus includes the eigenstates and energy dispersions being exactly the same as those of RS equations. By implementing our 16×16 or 6×6 Hamiltonian, one can realize the 3 dimensional or 2 dimensional (2D) massive RS quasiparticles in CMS, respectively. In the non-relativistic limit, the 2D 6×6 Hamiltonian can be reduced to two 3×3 Hamiltonians which describe the positive and negative energy parts respectively. Due to the nontrivial constraints, this simplified 2D massive RS quasiparticle has an exotic property: it has vanishing orbital magnetic moment while its orbital magnetization is finite. Finally, we discuss the material realization of RS quasiparticle.

邀 请 人： 翁红明（电话：8264 9941）
联 系 人： 胡   颖（电话：8264 9361）