Directional Control of Single-Photon Routing in Asymmetric Quantum Beam Splitter Based on the Additional Quantum Dot

Abstract

We propose a novel scheme of a directional quantum splitter using two two-level quantum dots (QDs), infinite and semi-infinite plasmonic waveguides, and theoretically illustrate the directional controllable routing properties, such as reflection and transfer spectra, in proposed model via real space approach when single photons are of entrance into the semi-infinite waveguide. We consider the reflection and transfer properties on controlling the impact of several parameters, such as inter-particle distance, coupling strength, detuning and so on. The characteristics of our investigation is that when the frequency of the incoming single photon are nearly similar to one of eigenfrequencies of an additional QD, our proposed the system acts as a directional quantum splitter with a high transfer ratio toward the specific path. That is, the incident single photons could be come out of only one side of infinite waveguide with the transfer rate of over 0.5 because the additional QD absorbs the energy of single photons through the coherent interaction. These properties could be unlocked new opportunities to realize the quantum communication networks and quantum computation systems based on practical single-photon switch or quantum logic gates.