Rectification of light in the quantum regime

TL;DR

This paper demonstrates that optical rectification in a quantum regime using two coupled atoms is a multi-photon effect, achieving up to 70% rectification with specific excitation conditions.

Contribution

The study reveals that rectification in a two-atom waveguide system is a purely quantum multi-photon phenomenon, extending previous semi-classical findings.

Findings

Rectification reaches up to 70% with certain power levels.

Rectification is a purely multi-photon quantum effect.

Optimal rectification occurs when only one atom is excited.

Abstract

One of the missing elements for realising an integrated optical circuit is a rectifying device playing the role of an optical diode. A proposal based on a pair of two-level atoms strongly coupled to a one-dimenisonal waveguide showed a promising behavior based on a semi-classical study [Fratini et al., Phys. Rev. Lett. 113, 243601 (2014)]. Our study in the full quantum regime shows that, in such a device, rectification is a purely multi-photon effect. For an input field in a coherent state, rectification reaches up to $70\%$ for the range of power in which one of the two atoms is excited, but not both.