Waveguide transport mediated by strong coupling with atoms

Abstract: We investigate single photon scattering properties in one-dimensional waveguide coupled to quantum emitter's chain with dipole-dipole interaction (DDI). The photon transport is extremely sensitive to the location of the evanescently coupled emitters. The analytical expressions of reflection and transmission amplitudes for the chain containing two emitters with DDI are deduced by using real-space Hamiltonian. Two cases, where the two emitters symmetrically and asymmetrically couple to the waveguide, are discussed in detail. It shows that the reflection and transmission typical spectra split into two peaks due to the DDI. The Fano minimum in the spectra can also be used to estimate the strength of the DDI. Furthermore, the DDI makes spectra strongly asymmetric and create a transmission window in the region where there was zero transmission. The scattering spectra for the chain consisting of multi-emitters are also given. Our key finding is that DDI can broaden the frequency band width for high reflection when the chain consists of many emitters.