  We study the quantum correlation and quantum communication channel of both
free scalar and fermionic fields in de Sitter space, while the Planckian
modification presented by the choice of a particular $\alpha$-vacuum has been
considered. We show that the occurrence of degradation of quantum entanglement
between field modes for an inertial observer in curved space, due to the
radiation associated with its cosmological horizon. Comparing with standard
Bunch-Davies choice, the possible Planckian physics causes some extra decrement
on the quantum correlation, which may provide the means to detect quantum
gravitational effects via quantum information methodology in future. Beyond
single-mode approximation, we construct proper Unruh modes admitting general
$\alpha-$vacua, and find a convergent feature of both bosonic and fermionic
entanglements. In particular, we show that the convergent points of fermionic
entanglement negativity are dependent on the choice of $\alpha$. Moreover, an
one-to-one correspondence between convergent points $H_c$ of negativity and
zeros of quantum capacity of quantum channels in de Sitter space has been
proved.
