- Letter
Second-order topological states in a sixfold symmetric quasicrystal
Phys. Rev. B 109, L121403 – Published 13 March, 2024
DOI: https://doi.org/10.1103/PhysRevB.109.L121403
Abstract
Recently, higher-order topology has been expanded to encompass aperiodic quasicrystals, including those with eightfold or twelvefold rotational symmetry. The underlying mechanism for these high-order topological phases is generally protected by symmetry, resulting in the presence of corner states. However, this mechanism is not applicable to other quasicrystals when is an odd number. In this work, we propose the realization of a second-order topological superconductor (SOTSC) within a sixfold symmetric bronze-mean hexagonal quasicrystal with six Majorana zero-energy modes. This SOTSC emerges from the combination of vertical and horizontal mirror symmetries, which flips the mass-term sign along the horizontal mirror-invariant line and produces Majorana zero-energy modes at each corner of the quasicrystal sample. Moreover, this mechanism can extend to quasicrystals with and rotational symmetries, namely encompassing systems with symmetry. Our findings provide useful guidance for achieving SOTSC in quasicrystals featuring rotational symmetry and introduce bronze-mean hexagonal quasicrystals as a promising platform for exploring quasicrystal SOTSC.