Figure 2: Phase response.
From: Ensemble-averaged Rabi oscillations in a ferromagnetic CoFeB film
(a) Dependence of the phase responses on the applied field at 10 GHz. Data set of Fig. 1f is presented in a two-dimensional contour plot to represent the phase information. Each temporal response was normalized individually. Blue curved guiding line indicates the location of the valley in Fig. 1f. (b) Phase response before the perturbation. The figure presents a close-up of the black dashed area of a for times between −300 and −100 ps. An overall phase shift of ∼0.75 π is measured across the resonance as indicated by the vertical black dashed lines representing the phase front at highest and lowest applied fields. Data are not normalized. (c) Phase response at long delays corresponding to black dashed area in a for times between 2,200 and 2,400 ps. Data are presented in normalized units. The measured net phase shift across the resonance is ∼2.75 π. Black dashed lines represent the phase front at highest and lowest applied fields. (d) Instantaneous frequency profiles at μ0H0 values of 424 mT (blue), 444 mT (red) and 468 mT (yellow) corresponding the blue, red and yellow dashed lines of a, respectively. Inset illustrates the decomposition of the total response to the steady state response of the system at ωRF and the natural response at the angular frequency of γμ0H0. The same reasoning also accounts for the asymmetry seen in the responses of Fig. 1f.
