  Realization of an on-chip quantum network is a major goal in the field of
integrated quantum photonics. A typical network scalable on-chip demands
optical integration of single photon sources, optical circuitry and detectors
for routing and processing of quantum information. Current solutions either
notoriously experience considerable decoherence or suffer from extended
footprint dimensions limiting their on-chip scaling. Here we propose and
numerically demonstrate a robust on-chip quantum network based on an
epsilon-near-zero (ENZ) material, whose dielectric function has the real part
close to zero. We show that ENZ materials strongly protect quantum information
against decoherence and losses during its propagation in the dense network. As
an example, we model a feasible implementation of an ENZ network and
demonstrate that quantum information can be reliably sent across a titanium
nitride grid with a coherence length of 434 nm, operating at room temperature,
which is more than 40 times larger than state-of-the-art plasmonic analogs. Our
results facilitate practical realization of large multi-node quantum photonic
networks and circuits on-a-chip.
