Magnon

A magnon is a collective excitation of the electrons' spin structure in a crystal lattice.

In the equivalent wave picture of quantum mechanics, a magnon can be viewed as a quantized spin wave. As a quasiparticle, a magnon carries a fixed amount of energy and lattice momentum. It also possesses a spin of ħ (where ħ is the reduced Planck constant).

In contrast, a phonon is a collective excitation of the crystal lattice atoms or ions.