Quantum communications feasibility tests over a UK-Ireland 224-km undersea link

TL;DR

This study demonstrates the feasibility of quantum communication over a 224 km submarine optical fibre link between the UK and Ireland, highlighting its potential for international quantum internet applications.

Contribution

It provides the first feasibility assessment of quantum communications over an undersea fibre link between the UK and Ireland, including characterisation of key quantum signal stability factors.

Findings

Successful phase drift and polarisation stability measurements

Demonstrated suitability for quantum communication over the undersea link

First international quantum communication feasibility test between UK and Ireland

Abstract

The future quantum internet will leverage existing communication infrastructures, including deployed optical fibre networks, to enable novel applications that outperform current information technology. In this scenario, we perform a feasibility study of quantum communications over an industrial 224 km submarine optical fibre link deployed between Southport in the United Kingdom (UK) and Portrane in the Republic of Ireland (IE). With a characterisation of phase drift, polarisation stability and arrival time of entangled photons, we demonstrate the suitability of the link to enable international UK-IE quantum communications for the first time.