Networking Molecular Quantum Emitters on a Single Chain : From Single to Cooperative Emitters

TL;DR

This paper introduces Encoded Quantum Chains (EQC), a scalable molecular architecture within boron nitride nanotubes that enables controlled cooperative light-matter interactions and enhanced emission properties for quantum photonic applications.

Contribution

The authors develop a novel one-dimensional molecular architecture, EQC, allowing precise control of emitter spacing and cooperative interactions in solid-state systems.

Findings

Enhanced radiative decay rates observed at sub-wavelength spacings.

Emergence of non-mono-exponential fluorescence dynamics indicating cooperative states.

Dimensional crossover observed when coupling between neighboring nanotubes occurs.

Abstract

Engineering light-matter interactions between multiple free-space quantum emitters is a central challenge for scalable quantum photonic technologies. In particular, accessing regimes of coherent emitter-emitter interactions, where several emitters are coupled through a shared electromagnetic environment, is essential for coherent emission and quantum functionalities. Such interactions require precise control over emitter separation and stabilization at sub-wavelength distances, a level of spatial organization that remains extremely difficult to achieve at the molecular scale in solid-state systems. Here we introduce Encoded Quantum Chains (EQC), a one-dimensional architecture in which cooperative radiative behaviour is programmed through spatial encoding of identical molecular emitters. Organic emitters and inert spacer molecules are co-encapsulated inside dielectric boron nitride nanotubes (BNNTs), enabling statistical control of intermolecular spacing from nanometres to micrometres while enforcing dipole alignment and one-dimensional confinement. Time-resolved fluorescence under ambient conditions reveals accelerated radiative decay, enhanced emission rates per emitter, and the emergence of non-mono-exponential dynamics as spacing falls below the optical wavelength, consistent with cooperative radiative states in one dimension. Bundling of EQCs enables coupling between emitters in neighbouring BNNTs, driving a dimensional crossover toward higher-dimensional delocalisation of the excitation. This modular building-block approach provides a scalable route to engineer light-matter interactions and many-body optical phenomena in confined molecular systems, opening new opportunities for distributed single-photon sources, programmable quantum emitters, and photonic architectures for quantum technologies.