Generation of phonon quantum states and quantum correlations among single photon emitters in hexagonal boron nitride

TL;DR

This paper demonstrates how hexagonal boron nitride's defects and topologically-protected phonons can be used to generate and transmit quantum states and correlations, advancing quantum information technology applications.

Contribution

It introduces a model showing phonons in boron nitride can transmit information and couple distant emitters, a novel approach for quantum communication.

Findings

Single SPEs can induce various phonon states.

Two SPEs can be strongly quantum correlated via TPL.

The material offers a nano-architecture for quantum devices.

Abstract

Hexagonal boron nitride exhibits two types of defects with great potential for quantum information technologies: single-photon emitters (SPEs) and one-dimensional grain boundaries hosting topologically-protected phonons, termed as {\it{topologically-protected phonon lines}} (TPL). Here, by means of a simple effective model and density functional theory calculations, we show that it is possible to use these phonons for the transmission of information. Particularly, a single SPE can be used to induce single-, two- and qubit-phonon states in the one dimensional channel, and \textit{(ii)} two distant SPEs can be coupled by the TPL that acts as a waveguide, thus exhibiting strong quantum correlations. We highlight the possibilities offered by this material-built-in nano-architecture as a phononic device for quantum information technologies.