Realization of Massive Relativistic Spin-3/2 Rarita-Schwinger Quasiparticle in Condensed Matter Systems
Prof. Xian-Gang Wan
School of Physics, Nanjing University

The spin-3/2 elementary particle, known as Rarita-Schwinger (RS) fermion, is described by a vector-spinor field {\psi}_{{\mu}{\alpha}}, whose number of components is larger than its independent degrees of freedom (DOF). Thus 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. 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 16X16 or 6X6 Hamiltonian, one can realize the 3 dimensional or 2 dimensional (2D) massive RS quasiparticles, respectively. In the non-relativistic limit, the 2D 6X6 Hamiltonian can be reduced to two 3X3 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. Our study provides an opportunity to realize higher spin elementary fermions with constraints in condensed matter systems.

About the Speaker

万贤纲, 教授, 博士生导师。1990-2000年在南京大学学习, 获博士学位。2001年留校任教。期间2003年10月至2005年2月日本国立材料研究所博士后, 2005年6月至2007年9月美国加州大学戴维斯分校访问。2010年南京大学任教授。主要从事凝聚态理论方面工作。2015年获基金委杰出青年基金资助, 2016年获教育部长江学者特聘教授资助。

2018-02-06 10:30 AM
Room: A303 Meeting Room
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