  Quantum communication demands efficient distribution of quantum entanglement
across a network of connected partners. The search for efficient strategies for
the entanglement distribution may be based on percolation theory, which
describes evolution of network connectivity with respect to some network
parameters. In this framework, the probability to establish perfect
entanglement between two remote partners decays exponentially with the distance
between them before the percolation transition point, which unambiguously
defines percolation properties of any classical network or lattice. Here we
introduce quantum networks created with local operations and classical
communication, which exhibit non-classical percolation transition points
leading to the striking communication advantages over those offered by the
corresponding classical networks. We show, in particular, how to establish
perfect entanglement between any two nodes in the simplest possible network --
the 1D chain -- using imperfect entangled pairs of qubits.
