Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of topologically protected helical edge modes in Kagome
  elastic plates   The investigation of topologically protected waves in classical media has
opened unique opportunities to achieve exotic properties like one-way phonon
transport, protection from backscattering and immunity to imperfections.
Contrary to acoustic and electromagnetic domains, their observation in elastic
solids has so far been elusive due to the presence of both shear and
longitudinal modes and their modal conversion at interfaces and free surfaces.
  Here we report the experimental observation of topologically protected
helical edge waves in elastic media. The considered structure consists of an
elastic plate patterned according to a Kagome architecture with an accidental
degeneracy of two Dirac cones induced by drilling through holes. The careful
breaking of symmetries couples the corresponding elastic modes which
effectively emulates spin orbital coupling in the quantum spin Hall effect.
  The results shed light on the topological properties of the proposed plate
waveguide and opens avenues for the practical realization of compact, passive
and cost-effective elastic topological waveguides.

30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci