Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological states in arrays of optical waveguides engineered via mode
  interference   Photonic structures with topologically nontrivial bands are usually designed
by arranging simple meta-atoms, ideally, single-mode ones, in a carefully
designed photonic lattice with symmetry that guarantees the emergence of
topological states. Here we investigate an alternative option that does not
require complex lattice geometry but instead relies on the tuning of the
parameters of the individual meta-atoms to achieve the degeneracy of the modes
with different symmetry. As an illustrative example, we consider a
one-dimensional array of equidistant identical periodic nanophotonic waveguides
supporting degenerate modes with strongly asymmetric near field profiles giving
rise to the coupling modulation. Exploiting this feature, we demonstrate that
the proposed system supports topological edge modes and can be viewed as a
generalization of the paradigmatic Su-Schrieffer-Heeger model, reducing to it
for the suitable parameter choice. Our results thus provide an avenue to
engineer topological states via mode interference which further expands the
plethora of topological structures available in photonics being especially
promising for nonlinear topological systems.

17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat