Al13Os4 is a monoclinic periodic approximant to the decagonal quasicrystal in which resistivity, magnetization, specific-heat, and muSR measurements reveal bulk superconductivity near 5.47 K, well described by weak-coupling BCS theory. First-principles calculations show a nontrivial Z2=1 topology with spin-polarized surface states and saddle-point van Hove singularities at the Fermi level. Learners study how quasicrystal approximants bridge periodic and aperiodic order and how superconductivity, band topology, and Fermi-level density-of-states peaks combine to make this a candidate for topological superconductivity.
This experimental condensed-matter study reports the discovery of superconductivity in Al13Os4, a monoclinic (space group C2/m) periodic approximant to the decagonal quasicrystal. Quasicrystals are a…