  We examine the propagation of single photons in periodic and disordered dimer
chains coupled to one-dimensional chiral and bidirectional waveguides. Each
dimer is composed of two dipole-coupled atoms. In the disordered setting, we
separately treat two types of position disorder, namely in dimer length and in
dimer separation. The focus of this study is to understand in what ways the
interplay between dipole-dipole interactions and directionality of photon
emission can impact the transport of single photons. Cold atoms trapped near
optical fibers can serve as an experimentally realizable platform for the
models that we consider.
