  Switchbacks are widely acknowledged phenomena observed by the Parker Solar
Probe and appear to occur in patches. Previous studies focused on the
fluctuations at the magnetic reversals. However, the nature of the fluctuations
inside the switchbacks remains unknown. Here we utilize the magnetic field data
and plasma data measured by the Parker Solar Probe in the first four
encounters. We investigate the fluctuations in the switchback intervals of 100
s with BR>0 at every instant and compare them to the fluctuations in the
nonswitchback intervals of 100 s with theta_RB>160o at every instant. We
calculate normalized cross-helicity sigma_c, normalized residual energy
sigma_r, correlation coefficient C_vb between dvA and dv, Alfven ratio rA, and
the amplitude of magnetic and kinetic fluctuations. We find that the switchback
intervals exhibit a distribution of sigma_c similar with the nonswitchback
intervals. However, the rA of switchback intervals is around 0.35, while the
nonswitchback intervals have rA around 0.65, indicating the fluctuations in the
switchbacks are more magnetically dominated. We also find that the distribution
pattern of pixel average amplitude of both dvA and dv of switchback intervals
in the C_vb-sigma_r plane show a vertical stripe feature at C_vb>0.8,
illustrating the possible magnetically dominant magnetic-velocity alignment
structure. These results will help us to understand the nature and the
formation of the switchback turbulence.
