Experimental investigation of high-dimensional quantum key distribution protocols with twisted photons

TL;DR

This paper presents an experimental platform using high-dimensional twisted photons to implement and compare various quantum key distribution protocols, assessing their noise tolerance and performance.

Contribution

It introduces a versatile experimental setup capable of implementing multiple QKD protocols with twisted photons, including the first experimental investigation of the differential phase shift protocol.

Findings

Successful implementation of multiple QKD protocols using twisted photons

Comparison of noise tolerance across different high-dimensional QKD techniques

First experimental analysis of the differential phase shift protocol in high dimensions

Abstract

Quantum key distribution is on the verge of real world applications, where perfectly secure information can be distributed among multiple parties. Several quantum cryptographic protocols have been theoretically proposed and independently realized in different experimental conditions. Here, we develop an experimental platform based on high-dimensional orbital angular momentum states of single photons that enables implementation of multiple quantum key distribution protocols with a single experimental apparatus. Our versatile approach allows us to experimentally survey different classes of quantum key distribution techniques, such as the 1984 Bennett \& Brassard (BB84), tomographic protocols including the six-state and the Singapore protocol, and to investigate, for the first time, a recently introduced differential phase shift (Chau15) protocol using twisted photons. This enables us to experimentally compare the performance of these techniques and discuss their benefits and deficiencies in terms of noise tolerance in different dimensions.