Optical control of collective states in 1D ordered atomic chains beyond the linear regime

TL;DR

This paper proposes a theoretical protocol using a 1D chain of three-level atoms to control collective states beyond the linear regime, enabling efficient atom-photon interfaces and entanglement characterization.

Contribution

It introduces a novel method to coherently transfer excitations between superradiant and subradiant states in a nonlinear regime of atomic chains.

Findings

Doubly-excited states can be coherently transferred between superradiant and subradiant states.

The protocol enables absorption, storage, and on-demand emission of photons in a controlled manner.

The boundary between linear and nonlinear regimes is established considering quantum atomic nature.

Abstract

Driven by the need to develop efficient atom-photon interfaces, recent efforts have proposed replacing cavities by large arrays of cold atoms that can support subradiant or superradiant collective states. In practice, subradiant states are decoupled from radiation, which constitutes a hurdle to most applications. In this work, we study theoretically a protocol that bypasses this limit using a one dimensional (1D) chain composed of N three-level atoms in a V-shaped configuration. Throughout the protocol, the chain behaves as a time-varying metamaterial: enabling absorption, storage and on-demand emission in a spectrally and spatially controlled mode. Taking into account the quantum nature of atoms, we establish the boundary between the linear regime and the nonlinear regime. In the nonlinear regime, we demonstrate that doubly-excited states can be coherently transferred from superradiant to subradiant states, opening the way to the optical characterization of their entanglement.