Figure 3

Spin wave state on the Bloch sphere.
A spin wave state labeled by (θ, ϕ) corresponds to an elliptical precession of the Néel order illustrated in the right panel.
Spin wave state on the Bloch sphere.
A spin wave state labeled by (θ, ϕ) corresponds to an elliptical precession of the Néel order illustrated in the right panel.