  We study various super-activation effects in the following zero-error
communication scenario: One sender wants to send classical or quantum
information through a noisy quantum channel to one receiver with zero
probability of error. First we show that there are quantum channels of which a
single use is not able to transmit classical information perfectly yet two uses
can. This is achieved by employing entangled input states between different
uses of the given channel and thus cannot happen for classical channels. Second
we exhibit a class of quantum channel with vanishing zero-error classical
capacity such that when a noiseless qubit channel or one ebit shared
entanglement are available, it can be used to transmit $\log_2 d$ noiseless
qubits, where 2d is the dimension of input state space. Third we further
construct quantum channels with vanishing zero-error classical capacity when
assisted with classical feedback can be used to transmit both classical and
quantum information perfectly. These striking findings not only indicate both
the zero-error quantum and classical capacities of quantum channels satisfy a
strong super-additivity beyond any classical channels, but also highlight the
activation power of auxiliary physical resources in zero-error communication.
