  Weyl nodes have been experimentally realized in photonic, electronic, and
phononic crystals. However, magnonic Weyl nodes are yet to be seen
experimentally. In this paper, we propose Weyl magnon nodes in noncoplanar
stacked frustrated kagome antiferromagnets, naturally available in various real
materials. Most crucially, the Weyl nodes in the current system occur at the
lowest excitation and possess a topological (anomalous) thermal Hall effect,
therefore they are experimentally accessible at low temperatures due to the
population effect of bosonic quasiparticles. In stark contrast to other
magnetic systems, the current Weyl nodes do not rely on time-reversal symmetry
breaking by the magnetic order. Rather, they result from explicit
macroscopically broken time reversal symmetry by the scalar spin chirality of
noncoplanar spin textures, and can be generalized to chiral spin liquid states.
Moreover, the scalar spin chirality gives a real space Berry curvature which is
not available in previously studied magnetic Weyl systems. We show the
existence of magnon arc surface states connecting projected Weyl magnon nodes
on the surface Brillouin zone. We also uncover the first realization of
triply-degenerate nodal magnon point in the non-collinear regime with zero
scalar spin chirality.
