T-shaped Single-photon Router

TL;DR

This paper investigates how a two-level system in a T-shaped waveguide can control single-photon transfer, showing boundary effects can enhance transfer rates up to unity from the semi-infinite waveguide.

Contribution

It reveals the boundary's role in boosting photon transfer efficiency in a T-shaped waveguide with a two-level system.

Findings

Boundary enhances transfer rate from semi-infinite CRW

Transfer rate can reach unity for certain incident directions

Transport properties depend on waveguide boundary conditions

Abstract

We study the transport properties of a single photon scattered by a two-level system (TLS) in a T-shaped waveguide, which is made of two coupled-resonator waveguides (CRWs)--- an infinite CRW and a semi-infinite CRW. The spontaneous emission of the TLS directs single photons from one CRW to the other. Although the transfer rate is different for the wave incident from different CRWs, due to the boundary breaking the translational symmetry, the boundary can enhance the transfer rate found in Phys. Rev. Lett. 111, 103604 (2013) and Phys. Rev. A 89, 013805 (2014), as the transfer rate could be unity for the wave incident from the semi-infinite CRW.