  We define a new phenomenon for communication over noisy quantum channels. The
investigated solution is called polaractivation and based on quantum polar
encoding. Polaractivation is a natural consequence of the channel polarization
effect in quantum systems and makes possible to open the hidden capacity
regions of a noisy quantum channel by using the idea of rate increment. While
in case of a classical channel only the rate of classical communication can be
increased, in case of a quantum channel the channel polarization and the rate
improvement can be exploited to open unreachable capacity regions. We
demonstrate the results for the opening of private classical capacity-domain.
We prove that the method works for arbitrary quantum channels if a given
criteria in the symmetric classical capacity is satisfied. We also derived a
necessary lower bound on the rate of classical communication for the
polaractivation of private classical capacity-domain.
