Single-photon coherent transparency in a coupled atoms-waveguide system

TL;DR

This paper studies how single photons propagate through a waveguide coupled to multiple atoms, revealing that atomic number and arrangement can control photon transparency and reflection, with potential for tunable quantum photonic devices.

Contribution

It demonstrates how the number and positioning of atoms in a waveguide influence single-photon transparency and reflection, introducing a method to control photon transport.

Findings

Transparency occurs for even N at resonance due to coherent interactions.

Odd N results in full photon reflection at resonance.

Photon transport can be switched by controlling atomic number.

Abstract

We investigate the single-photon propagation in the one-dimensional waveguide coupled to $N$ two-level atoms. For a waveguide coupled to $N$ distant atoms, the transparency can be induced by coherent interaction at resonance for an $even$ $number$ of $N$, while for an $odd$ $number$ of $N$, the photon can be fully reflected. We then can switch the photon transport by controlling the atomic number. For a waveguide coupled to a small atomic ensemble of $N$ atoms in the same position, the transparency disappears, and the photonic transport property displays a jump behavior near the resonance point.