论文标题
由连续旋转对称保护保护的无定形拓扑相
Amorphous topological phases protected by continuous rotation symmetry
论文作者
论文摘要
当样品的边界与晶体的高对称平面未对准时，通过反射对称对拓扑表面状态的保护会分解。我们证明，这种限制是在无定形拓扑材料中去除的，由于连续旋转对称性，在任何轴上，哈密顿量平均在反射下平均不变。尽管无定形结构引起的局部疾病削弱了拓扑保护，但我们证明了边缘仍然可以保护不受本地化的保护。为了对此类阶段进行分类，我们在两个维度上对所有可能的对称类别进行系统搜索，并构建实现每个提出的拓扑阶段的示例模型。最后，我们将这些阶段的拓扑不变性视为沿着无定形哈密顿量球形布里鲁因区的子午线的积分。
Protection of topological surface states by reflection symmetry breaks down when the boundary of the sample is misaligned with one of the high symmetry planes of the crystal. We demonstrate that this limitation is removed in amorphous topological materials, where the Hamiltonian is invariant on average under reflection over any axis due to continuous rotation symmetry. While the local disorder caused by the amorphous structure weakens the topological protection, we demonstrate that the edge remains protected from localization. In order to classify such phases we perform a systematic search over all the possible symmetry classes in two dimensions and construct the example models realizing each of the proposed topological phases. Finally, we compute the topological invariant of these phases as an integral along a meridian of the spherical Brillouin zone of an amorphous Hamiltonian.
