Topological Phases without Crystalline Counterparts

Journal article (2019)

Authors

D. Varjas Kavli institute of nanoscience Delft, QuTech Advanced Research Centre, QRD/Kouwenhoven Lab - QuTech Advanced Research Centre
A. Lau Kavli institute of nanoscience Delft, QN/Akhmerov Group - AS
K.K. Pöyhönen QRD/Wimmer Group - QuTech Advanced Research Centre , Kavli institute of nanoscience Delft, QuTech Advanced Research Centre
A.R. Akhmerov Kavli institute of nanoscience Delft, QN/Akhmerov Group - AS
Dmitry I. Pikulin University of California
Ion Cosma Fulga IFW Dresden
Research Group
QRD/Kouwenhoven Lab (QuTech Advanced Research Centre) (TU Delft)
Copyright: © 2019 D. Varjas, A. Lau, K.K. Pöyhönen, A.R. Akhmerov, Dmitry I. Pikulin, Ion Cosma Fulga
DOI
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https://doi.org/10.1103/PhysRevLett.123.196401
Majorana bound states Exotic phases of matter Symmetry protected topological states Topological materials
More Info
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Published Date

2019

Language

English

Faculty

QuTech Advanced Research Centre

Department

Qubit Research Division

Research Group

QRD/Kouwenhoven Lab

Abstract

We construct a two-dimensional higher-order topological phase protected by a quasicrystalline eightfold rotation symmetry. Our tight-binding model describes a superconductor on the Ammann-Beenker tiling hosting localized Majorana zero modes at the corners of an octagonal sample. In order to analyze this model, we introduce Hamiltonians generated by a local rule, and use this concept to identify the bulk topological properties. We find a Z2 bulk topological invariant protecting the corner modes. Our work establishes that there exist topological phases protected by symmetries impossible in a crystal.