Wallpaper fermions and the nonsymmorphic Dirac insulator

Benjamin J. Wieder, Barry Bradlyn, Zhijun Wang, Jennifer Cano, Youngkuk Kim, Hyeong Seok D. Kim, Andrew M. Rappe, C. L. Kane, B. Andrei Bernevig

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127 Scopus citations


Materials whose gapless surface states are protected by crystal symmetries include mirror topological crystalline insulators and nonsymmorphic hourglass insulators. There exists only a very limited set of possible surface crystal symmetries, captured by the 17 “wallpaper groups.” Here we show that a consideration of symmetry-allowed band degeneracies in the wallpaper groups can be used to understand previously described topological crystalline insulators and to predict phenomenologically distinct examples. In particular, the two wallpaper groups with multiple glide lines, pgg and p4g, allow for a topological insulating phase whose surface spectrum consists of only a single, fourfold-degenerate, true Dirac fermion, representing an exception to a symmetry-enhanced fermion-doubling theorem. We theoretically predict the presence of this phase in Sr2Pb3 in space group 127 (P4/mbm).

Original languageEnglish (US)
Pages (from-to)246-251
Number of pages6
Issue number6399
StatePublished - Jul 20 2018

All Science Journal Classification (ASJC) codes

  • General

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