# T-bulge single photon quantum router with three level system

## TL;DR

This paper investigates the transmission properties of a T-bulge quantum router formed by a three-level system at the intersection of infinite and semi-infinite coupled-resonator waveguides, revealing boundary effects on transfer rates.

## Contribution

It introduces the T-bulge structure with a three-level system and analyzes how boundary conditions affect transmission, providing detailed visualizations of the transmission characteristics.

## Key findings

- Maximum transfer rate reaches unity from semi-infinite CRW
- Transfer rate is 0.5 when incident from infinite CRW
- Position of intersection influences transmission coefficients

## Abstract

This paper considers the transmission characteristics of incidenting from an infinte coupled-resonator waveguide (CRW) or a semi-infinite CRW, respectively. The Nth cavity of a semi-infinite CRW intersecting with an infinite CRW and a cascade three level system(CTLS) form a T-bulge structure. Due to symmetry breaking boundary, the maximum of transfer rate would reach unity when light incidenting from the semi-infinite CRW, while reach 0.5 for infinite CRW case. The position of the intersection have effect on the location of the extreme point of the transmission coefficients changing with couple strength. 4D figures are used to illustrate the transmission characteristics, which is more visable.