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Symmetry-Protected Topological relationship between $SU(3)$ and $SU(2)times{U(1)}$ in Two Dimension

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 نشر من قبل Qiao Zhuang
 تاريخ النشر 2021
  مجال البحث فيزياء
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Symmetry-protected topological $left(SPTright)$ phases are gapped short-range entangled states with symmetry $G$, which can be systematically described by group cohomology theory. $SU(3)$ and $SU(2)times{U(1)}$ are considered as the basic groups of Quantum Chromodynamics and Weak-Electromagnetic unification, respectively. In two dimension $(2D)$, nonlinear-sigma models with a quantized topological Theta term can be used to describe nontrivial SPT phases. By coupling the system to a probe field and integrating out the group variables, the Theta term becomes the effective action of Chern-Simons theory which can derive the response current density. As a result, the current shows a spin Hall effect, and the quantized number of the spin Hall conductance of SPT phases $SU(3)$ and $SU(2)times{U(1)}$ are same. In addition, relationships between $SU(3)$ and $SU(2)times{U(1)}$ which maps $SU(3)$ to $SU(2)$ with a rotation $U(1)$ will be given.



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