High-dimensional quantum communication: benefits, progress, and future challenges

TL;DR

This paper reviews the advancements in high-dimensional quantum states, highlighting their benefits like increased information capacity and noise resilience, and discusses recent experimental progress in their generation, propagation, and detection.

Contribution

It provides a comprehensive overview of current techniques and experimental achievements in high-dimensional quantum communication, emphasizing recent progress and future challenges.

Findings

High-dimensional states offer larger information capacity.

Experimental demonstrations show advantages over two-dimensional systems.

Various channels successfully propagate high-dimensional quantum states.

Abstract

In recent years, there has been a rising interest in high-dimensional quantum states and their impact on quantum communication. Indeed, the availability of an enlarged Hilbert space offers multiple advantages, from larger information capacity and increased noise resilience, to novel fundamental research possibilities in quantum physics. Multiple photonic degrees of freedom have been explored to generate high-dimensional quantum states, both with bulk optics and integrated photonics. Furthermore, these quantum states have been propagated through various channels, \textit{e.g.} free-space links, single-mode, multicore, and multimode fibers and also aquatic channels, experimentally demonstrating the theoretical advantages over two-dimensional systems. Here, we review the state of the art on the generation, the propagation and the detection of high-dimensional quantum states.