论文标题
滑行对称性受保护的高阶拓扑绝缘子免受蝴蝶状淋巴结线的半法
Glide Symmetry Protected Higher-Order Topological Insulators from Semimetals with butterfly-like Nodal Lines
论文作者
论文摘要
如今，在跨系统中发现的大多数拓扑绝缘子可以通过引入旋转轨道耦合（SOC）从拓扑半学（TSM）转换，从而消失了散装间隙，该旋转轨道耦合（SOC）表现出了间隙TI相之间的内在联系。最近，我们提出了一个新的TSM家族，该家族是在时间变换不变的{\ it无旋转}系统中，该系统托有由一对相同的同心相交Coplanar椭圆形组成的类似蝴蝶般的节点线（NLS）。在这种交流中，我们通过包括实质性的SOC，推出了这种异国情调的节点线半学（NLSMS）和$ \ Mathbb {z} _ {4} $ = 2拓扑结晶绝缘子（TCI）之间的内在联系。 We demonstrate that in three space groups ({\it i.e.} $Pbam$ (No.55), $P4/mbm$ (No.127) and $P4_2/mbc$ (No.135)), the TCI supports a fourfold Dirac fermion on the (001) surface protected by two glide symmetries, which originates from the intertwined drumhead surface states of the CICE NLs.一维螺旋铰链状态的出现进一步证明了高阶拓扑结构，表明由滑动对称性保护的新的高阶拓扑绝缘子。
Most topological insulators discovered today in spinful systems can be transformed from topological semimetals (TSMs) with vanishing bulk gap via introducing the spin-orbit coupling (SOC), which manifests the intrinsic links between the gapped TI phases and the gapless TSMs. Recently, we have proposed a new family of TSMs in time-reversal invariant {\it spinless} systems, which host butterfly-like nodal-lines (NLs) consisting of a pair of identical concentric intersecting coplanar ellipses (CICE). In this Communication, we unveil the intrinsic link between this exotic class of nodal-line semimetals (NLSMs) and a $\mathbb{Z}_{4}$ = 2 topological crystalline insulator (TCI), by including substantial SOC. We demonstrate that in three space groups ({\it i.e.} $Pbam$ (No.55), $P4/mbm$ (No.127) and $P4_2/mbc$ (No.135)), the TCI supports a fourfold Dirac fermion on the (001) surface protected by two glide symmetries, which originates from the intertwined drumhead surface states of the CICE NLs. The higher order topology is further demonstrated by the emergence of one-dimensional helical hinge states, indicating a new higher order topological insulator protected by a glide symmetry.
