  The Dzyaloshinskii-Moriya interaction (DMI), favoring a chiral spin structure
like the skyrmion, gives rise to the nonreciprocal propagation of spin waves.
We investigate the propagation of spin waves in a nanostripe with the presence
of a skyrmion chain by using micromagnetic simulations. Through applying a
microwave locally, it is found that when the interval between skyrmions is
large enough, the spin waves can be separated to the counter direction
according to different frequencies. While for the tightly arranged skyrmions,
the skyrmion chain with strong interactions between skyrmions becomes a channel
for spin waves, which is around the frequency of skyrmion breathing and exhibit
a characteristic of directional propagation. This work opens a vista for
skyrmion-based spin wave devices.
