  We propose a heralded quantum repeater based on the scattering of photons off
single emitters in one-dimensional waveguides. We show the details by
implementing nonlocal entanglement generation, entanglement swapping, and
entanglement purification modules with atoms in waveguides, and discuss the
feasibility of the repeater with currently achievable technology. In our
scheme, the faulty events can be discarded by detecting the polarization of the
photons. That is, our protocols are accomplished with fidelity of 100% in
principle, which is advantageous for implementing realistic long-distance
quantum communication. Moreover, additional atomic qubits are not required, but
only a single-photon medium. Our scheme is scalable and attractive since it can
be realized in solid-state quantum systems. With the great progress on
controlling atom-waveguide systems, the repeater may be very useful in quantum
information processing in the future.
