spin precession data of the Ni magnetic moment in an Ni81Fe19 sample

The energy of X-ray was fixed at the L3 absorption edge of Ni element and adjusted to circularly polarized light. In the experiment, microwave is generated on the surface of the central conductor of CPW, and the microwave triggers the electrons of magnetic elements to perform Larmor precession around the constant magnetic field direction.

The component of the spin magnetic moment along the X-ray direction changes periodically, and the absorption intensity of the X-ray also changes accordingly. During each measurement, the delay between pump and probe was changed (in this experiment, the step size was 20ps), that is, the phase difference was constantly changed, the electron spin precession curve is obtained by arranging the signal points measured at different time delays.