Table 2.
Space groups (SGs) that admit Dirac points with HOFA states derived from the QI introduced in ref. 23.
| Space groups admitting dirac points with HOFA states | ||
|---|---|---|
| Point group name | Point group symbol | SG numbers |
| C4v | 99–110 | |
| D4h | 123–142 | |
| Oh | 221–230 | |
All of these SGs have point groups that contain C4v. We obtain this list of SGs by combining the nested Jackiw–Rebbi formulation of the QI in Supplementary Note 6 with an analysis of the crystallographic rod groups in Supplementary Note 12. In all of these SGs, semimetals with Dirac points along lines with 4 mm or symmetry will exhibit intrinsic HOFA states when cut into nanorods that preserve fourfold axes and are thick compared with the in-plane lattice spacing. This list is a complete enumeration of the SGs that permit Dirac semimetals with HOFA states directly related to the QI introduced in ref. 23; alternative realizations of Dirac and Weyl semimetals with HOFA states derived from other 2D magnetic insulators with corner states are also possible (refs. 32,37 and Supplementary Note 12).