Fig. 2
From: Decoherence in spin wave propagation via precursor pulses during signal equilibration
(a) Comparison between the FFT of quasi-Heaviside step function with no time delay (green) and a 1 ns delay (orange) as shown in the insets. Both signals terminate arbitrarily at 10 ns. (b) Dispersion relation for our system which has been separated into three thematic cases. These cases are based upon the rate of change of the group velocity, shown in Eq. (5). The dashed, red line represents \(\omega = \gamma (H_0 + Dk^2)\) which is only valid in the limit \(ka \ll 1\).
