Fig. 7: Tracking signals in time domain at 7T using a 13C magnetometer.
From: High field magnetometry with hyperpolarized nuclear spins
A Long-time oscillatory response So under the chirped AC field in Fig. 6A. Signal shows a strong response as the instantaneous frequency cross resonance \({f}_{{{{{{{{\rm{res}}}}}}}}}\). B–D Tracking of AC frequency. Three 150 ms time windows are marked, and panels B–D show the corresponding Fourier transforms. Solid lines are Lorentzian fits. Clearly the 13C signal carries a real-time imprint of the frequency of the applied chirped AC magnetic field. A more detailed and complete account of this analysis is given in Fig. S8 including a short-time Fourier transform.
