  Given a proper smooth $p$-adic variety, we show a comparison theorem for the
$p$-adic Simpson correspondence constructed by Faltings and Riemann-Hilbert
correspondence constructed by Scholze. As an application we formulate a
sufficient condition for $\overline{\mathbb Q}_p$-local system being de Rham.
We study a $p$-adic analogue of Simpson's $\mathbb C^*$-action on the set of
isomorphism classes of Higgs bundles and the corresponding Galois action on the
set of isomorphism classes of generalized representations of the \'etale
fundamental group.
