Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological magnon insulators in two-dimensional van der Waals
  ferromagnets CrSiTe$_3$ and CrGeTe$_3$: towards intrinsic gap-tunability   The bosonic analogues of topological insulators have been proposed in
numerous theoretical works, but their experimental realization is still very
rare, especially for spin systems. Recently, two-dimensional (2D) honeycomb van
der Waals (vdW) ferromagnets have emerged as a new platform for topological
spin excitations. Here, via a comprehensive inelastic neutron scattering study
and theoretical analysis of the spin-wave excitations, we report the
realization of topological magnon insulators in CrXTe$_3$ (X=Si, Ge) compounds.
The nontrivial nature and intrinsic tunability of the gap opening at the magnon
band-crossing Dirac points are confirmed, while the emergence of the
corresponding in-gap topological edge states is demonstrated theoretically. The
realization of topological magnon insulators with intrinsic gap-tunability in
this class of remarkable 2D materials will undoubtedly lead to new and
fascinating technological applications in the domain of magnonics and
topological spintronics.

24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas