  Topological magnon modes are expected to be useful for novel applications
such as robust information propagation, since they are immune to backscattering
and robust against disorder. Although there are several of theoretical
proposals for topological magnon modes and growing experimental efforts for
realizing them by now, it is still desirable to add complementary insights on
this important phenomenon. Here, we propose a new scheme to achieve topological
magnon where only nearest-neighbour exchange couplings on honeycomb lattice are
necessary. In both ferromagnets and antiferromagnets, tuning exchange couplings
between and inside hexagonal unit cells induces a topological state accompanied
by a band inversion between p-orbital and d-orbital like magnon modes.
Topological magnon modes appear at the interface between a topological domain
and a trivial domain with magnon currents, which counterpropagate depending on
pseudospins originated from orbital angular momenta of magnon modes. This
mimics the spin-momentum locking phenomenon in the quantum spin Hall effect.
