Fig. 3: Signal analysis of the Bethe Ansatz.
From: Quantum wake dynamics in Heisenberg antiferromagnetic chains
The right column is the Fourier Transform of the left. a, c, e The Bethe Ansatz with everything removed but key features at Q = π or Q = π/2. b, d, f The resulting Fourier transform of these spectra into real space and time. This clearly shows that the oscillations above the light cone are due to the stationary Q = π/2 states, while the light cone is due to the dispersive Q = π state. g The G(r, t) of the Bethe Ansatz with all correlations above the light cone set to zero. Fourier-transforming this back into S(Q, ω) in h, we find a spinon spectrum with the Q = π/2 stationary states missing---confirming that these are responsible for the oscillating Floquet dynamics.
