Print Email Facebook Twitter Topological defects in a double-mirror quadrupole insulator displace diverging charge Title Topological defects in a double-mirror quadrupole insulator displace diverging charge Author Araya Day, I.M. (TU Delft QRD/Wimmer Group; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Akhmerov, A.R. (TU Delft QN/Akhmerov Group; Kavli institute of nanoscience Delft) Varjas, Dániel (Stockholm University) Date 2022 Abstract We show that topological defects in quadrupole insulators do not host quantized fractional charges, contrary to what their Wannier representation indicates. In particular, we test the charge quantization hypothesis based on the Wannier representation of a disclination and a parametric defect. Since disclinations necessarily strain the lattice and parametric defects require closed curves in parameter space, both defects break four-fold rotation symmetry, even away from their origin. The Wannier representation of the defects is thus determined by local reflection symmetries. Contrary to the hypothesis, we find that the local charge density decays as ∼ 1/r2 with distance, leading to a diverging defect charge. Because topological defects are incompatible with four-fold rotation symmetry, we conclude that defect charge quantization is protected by sublattice symmetry, and not higher order topology. To reference this document use: http://resolver.tudelft.nl/uuid:61332adc-1318-4a81-a3ae-756b3b38acbc DOI https://doi.org/10.21468/SciPostPhysCore.5.4.053 ISSN 2666-9366 Source SciPost Physics Core, 5 (4) Part of collection Institutional Repository Document type journal article Rights © 2022 I.M. Araya Day, A.R. Akhmerov, Dániel Varjas Files PDF SciPostPhysCore_5_4_053.pdf 978.1 KB Close viewer /islandora/object/uuid:61332adc-1318-4a81-a3ae-756b3b38acbc/datastream/OBJ/view