  We show that the energy-transport efficiency in a chain of two-level emitters
can be drastically enhanced by the presence of a photonic topological insulator
(PTI). This is obtained by exploiting the peculiar properties of its
nonreciprocal surface plasmon polariton (SPP), which is unidirectional, and
immune to backscattering, and propagates in the bulk band gap. This
amplification of transport efficiency can be as much as 2 orders of magnitude
with respect to reciprocal SPPs. Moreover, we demonstrate that despite the
presence of considerable imperfections at the interface of the PTI, the
efficiency of the SPP-assisted energy transport is almost unaffected by
discontinuities. We also show that the SPP properties allow energy transport
over considerably much larger distances than in the reciprocal case, and we
point out a particularly simple way to tune the transport. Finally, we analyze
the specific case of a two-emitter chain and unveil the origin of the
efficiency amplification. The efficiency amplification and the practical
advantages highlighted in this work might be particularly useful in the
development of new devices intended to manage energy at the atomic scale.
