论文标题
由$ C_2 $对称及其边界理论保护的4D超越拓扑阶段
4D beyond-cohomology topological phase protected by $C_2$ symmetry and its boundary theories
论文作者
论文摘要
我们研究了$ c_ {2} $在四个空间维度中的旋转对称性的玻色谱对称拓扑（SPT）阶段，而小组共同体分类未捕获。通过使用拓扑晶体方法，我们表明该SPT相的拓扑结晶状态是通过将$ e_ {8} $状态放在二维旋转不变平面上给出的，该平面提供了此阶段的简单物理图片。基于这种理解，我们表明QED4具有Charge-1和Charge-3 Dirac Fermions的变体是三维边界的字段理论描述。我们还讨论了与拓扑顺序及其异常特征与对称差边界的联系。
We study bosonic symmetry protected topological (SPT) phases with $C_{2}$ rotational symmetry in four spatial dimensions which is not captured by the group cohomology classification. By using the topological crystal approach, we show that the topological crystalline state of this SPT phase is given by placing an $E_{8}$ state on the two dimensional rotational invariant plane, which provides a simple physical picture of this phase. Based on this understanding, we show that a variant of QED4 with charge-1 and charge-3 Dirac fermions is a field theoretical description of the three dimensional boundary. We also discuss the connection to symmetric gapped boundary with topological order and its anomaly signature.
