Symmetry-protected topological polarons

The lattice distortions of self-trapped polarons have long been assumed to be trivial, and to consist of simple contractions or expansions of the lattice around the electron. This trend is what is typically observed in ab initio calculations of polarons. Recently, nontrivial vortex-like displacement patterns similar to magnetic skyrmions have been identified in halide perovskites, raising the question of whether such patterns might also exist in other materials classes. In this talk, we systematically investigate topologically nontrivial polaron textures in a broad range of materials using a group-theoretic analysis. We identify four inequivalent topological classes, and we validate predicted topological patterns via direct ab initio calculations. The discovery of universal topological quantization in polarons opens new opportunities for using these quasiparticles as information carriers in quantum technologies.