  Evidence for the presence of ion cyclotron waves, driven by turbulence, at
the boundaries of the current sheet is reported in this paper. By exploiting
the full potential of the joint observations performed by Parker Solar Probe
and the Metis coronagraph on board Solar Orbiter, local measurements of the
solar wind can be linked with the large-scale structures of the solar corona.
The results suggest that the dynamics of the current sheet layers generates
turbulence, which in turn creates a sufficiently strong temperature anisotropy
to make the solar-wind plasma unstable to anisotropy-driven instabilities such
as the Alfv\'en ion-cyclotron, mirror-mode, and firehose instabilities. The
study of the polarization state of high-frequency magnetic fluctuations reveals
that ion cyclotron waves are indeed present along the current sheet, thus
linking the magnetic topology of the remotely imaged coronal source regions
with the wave bursts observed in situ. The present results may allow
improvement of state-of-the-art models based on the ion cyclotron mechanism,
providing new insights into the processes involved in coronal heating.
