Robustness of a quasicrystalline higher-order topological insulator

It was recently discovered that quasicrystalline systems may provide a platform for the realisation of higher order topological insulators, where the topo-logical phase is protected by spatial symmetries. In this paper I focus on a specific model and study the robustness of its topological phase against perturbations of the protecting symmetry. This is done both by varying the shape of the sample and by deforming the lattice. While signatures of the higher order topological phase can persist, the effects of an even slight symmetry breaking are significant.