  Long-range coherent interactions between quantum emitters are instrumental
for quantum information and simulation technologies, but they are generally
difficult to isolate from dissipation. Here, we show how such interactions can
be obtained in photonic Weyl environments due to the emergence of an exotic
bound state whose wavefunction displays power-law spatial confinement. Using an
exact formalism, we show how this bound state can mediate coherent transfer of
excitations between emitters, with virtually no dissipation and with a transfer
rate that follows the same scaling with distance as the bound state
wavefunction. In addition, we show that the topological nature of Weyl points
translates into two important features of the Weyl bound state, and
consequently of the interactions it mediates: first, its range can be tuned
without losing the power-law confinement, and, second, they are robust under
energy disorder of the bath. To our knowledge, this is the first proposal of a
photonic setup that combines simultaneously coherence, tunability, long-range,
and robustness to disorder. These findings could ultimately pave the way for
the design of more robust long-distance entanglement protocols or quantum
simulation implementations for studying long-range interacting systems.

Quantum Physics;Materials Science;Optics