The dispersion of the quasi-particles in an itinerant compound is mapped out, as mostly represented by the curves and flat bands. The most intriguing feature is the pair of ears of a rabbit on the top, as a result of undefined energy. The whole image resembles a rabbit peeking right on us.
Every particle has its own relation between momentum and energy. By using the inelastic neutron scattering technique, the dispersions of phonon and magnon in a prototypical itinerant compound are mapped out in great details. The ear-like feature is a result of not-well-defined energy of a magnon hitting the Stoner's continuum at a fixed momentum. The dispersions of phonon and magnon in this compound are intertwined and complicated, however the whole dispersion looks amazing, resembling a curious rabbit peeking right on us and wondering what's happening.