Abstract Based on first-principles calculations and Wannier tight-binding model, a three-dimensional (3D) carbon structure, named mC16, composed of interpenetrating graphene, is shown to be a topological nodal-line semimetal. The band structure calculations reveal that mC16 exhibits some exceptional properties. These include the Dirac band and band inversion around the Fermi level, and four nodal-lines in the entire Brillouin zone, symmetrically distributed on both sides of the mirror plane, and protected by the PT symmetry. In addition, the topological “drumhead-like” surface states appear on the (001) surface of mC16 and the double “drumhead-like” flat surface state emerges on the type-II (001) surface of the 3D mC16 structure. Moreover, the exotic surface Dirac points are located on the type-I (001) surface, implying that mC16 may process interesting surface transport properties. These new features make mC16 a new member in the topological carbon family, with promising novel applications in electronic device.

中文翻译：

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单斜 C 16 : sp 2 - sp 3 杂化节线半金属受 PT 对称保护

摘要 基于第一性原理计算和万尼尔紧束缚模型，由互穿石墨烯组成的三维 (3D) 碳结构 mC16 被证明是一种拓扑节点线半金属。能带结构计算表明 mC16 表现出一些特殊的性质。其中包括费米能级周围的狄拉克能带和能带反转，以及整个布里渊区中的四个节点线，对称分布在镜面两侧，并受到 PT 对称性的保护。此外，拓扑“鼓头状”表面态出现在 mC16 的（001）表面，双“鼓头状”平面态出现在 3D mC16 结构的 II 型（001）表面。此外，奇异表面狄拉克点位于 I 型 (001) 表面上，这意味着 mC16 可能会处理有趣的表面传输特性。这些新特性使 mC16 成为拓扑碳家族的新成员，在电子设备中具有广阔的应用前景。