Giant atom-mediated single photon routing between two waveguides

Abstract

In this work, the single photon scattering due to a giant atom coupled with a pair of waveguides is investigated theoretically. Using the real-space Hamiltonian, four scattering amplitudes are obtained, and the single photon routing properties are studied. Calculations reveal that the single photon routing properties are strongly dependent on the size of the giant atom. The possible physical mechanism is also discussed. To improve routing efficiency, the configuration where one waveguide is terminated is further studied. The calculated results indicate that an incident photon can be transferred to the other waveguide with unit efficiency by choosing the appropriate configuration for a fixed size of the giant atom. Our results may be used in quantum information processing and design quantum devices at single-photon level.