Fig. 6.

Intensity of higher harmonics in the microwave radiation. Normalized emission power P_m as a function of the harmonics number m for a vortex velocity of v = 75 m s⁻¹. The assumed superposition of the em wave emission associated with the 100 Å spacing between the vortex rows (a) and the 50 Å-periodic layered structure (b) is used to explain the spectrum modification in c, d. The spectrum at 3 K (e) exhibits a stronger damping of higher harmonics as compared to 1.8 K (b). Symbols are P_m values deduced from the spectra in Fig. 2. Solid lines are fits as indicated. Error bars depict the doubled standard deviation encompassing about 95% of the data