@article{FritscheHoeckendorfAlvermannetal.2020,
  author    = {Fritsche, Alexander and H{\"o}ckendorf, Bastian and Alvermann, Andreas and Fehske, Holger},
  title     = {Real and imaginary edge states in stacked Floquet honeycomb lattices},
  series = {The European Physical Journal B},
  volume    = {93},
  journal   = {The European Physical Journal B},
  number    = {151},
  issn      = {1434-6028},
  doi       = {10.1140/epjb/e2020-10233-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232347},
  year      = {2020},
  abstract  = {We present a non-Hermitian Floquet model with topological edge states in real and imaginaryband gaps. The model utilizes two stacked honeycomb lattices which can be related via four different typesof non-Hermitian time-reversal symmetry. Implementing the correct time-reversal symmetry provides uswith either two counterpropagating edge states in a real gap, or a single edge state in an imaginary gap.The counterpropagating edge states allow for either helical or chiral transport along the lattice perimeter.In stark contrast, we find that the edge state in the imaginary gap does not propagate. Instead, it remainsspatially localized while its amplitude continuously increases. Our model is well-suited for realizing theseedge states in photonic waveguide lattices},
  language  = {en}
}
@article{VigliottiCalzonaTraversoZianietal.2023,
  author    = {Vigliotti, Lucia and Calzona, Alessio and Traverso Ziani, Niccol{\`o} and Bergeret, F. Sebastian and Sassetti, Maura and Trauzettel, Bj{\"o}rn},
  title     = {Effects of the spatial extension of the edge channels on the interference pattern of a helical Josephson junction},
  series = {Nanomaterials},
  volume    = {13},
  journal   = {Nanomaterials},
  number    = {3},
  issn      = {2079-4991},
  doi       = {10.3390/nano13030569},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304846},
  year      = {2023},
  abstract  = {Josephson junctions (JJs) in the presence of a magnetic field exhibit qualitatively different interference patterns depending on the spatial distribution of the supercurrent through the junction. In JJs based on two-dimensional topological insulators (2DTIs), the electrons/holes forming a Cooper pair (CP) can either propagate along the same edge or be split into the two edges. The former leads to a SQUID-like interference pattern, with the superconducting flux quantum ϕ\(_0\) (where ϕ\(_0\)=h/2e) as a fundamental period. If CPs' splitting is additionally included, the resultant periodicity doubles. Since the edge states are typically considered to be strongly localized, the critical current does not decay as a function of the magnetic field. The present paper goes beyond this approach and inspects a topological JJ in the tunneling regime featuring extended edge states. It is here considered the possibility that the two electrons of a CP propagate and explore the junction independently over length scales comparable to the superconducting coherence length. As a consequence of the spatial extension, a decaying pattern with different possible periods is obtained. In particular, it is shown that, if crossed Andreev reflections (CARs) are dominant and the edge states overlap, the resulting interference pattern features oscillations whose periodicity approaches 2ϕ\(_0\).},
  language  = {en}
}