We propose an efficient single-photon router comprising two resonator waveguide channels coupled by several sequential cavities with embedded three-level atoms. We show that the system can operate as a perfect four-way single-photon switch. We also demonstrate that an incident single-photon propagating in one of the waveguides can be routed into one or the other output channels; such routing can be controlled by the external classical electromagnetic field driving the atoms. We argue that, under appropriate conditions, the efficiency of such routing can be close to 100\% within a broad operational bandwidth, suggesting various applications in photonics.
@article{arxiv.1901.08916,
title = {A tunable single photon quantum router},
author = {M. Ahumada and P. A. Orellana and F. Domínguez-Adame and A. V. Malyshev},
journal= {arXiv preprint arXiv:1901.08916},
year = {2019}
}