# Efficient High-dimensional Quantum Key Distribution with Hybrid Encoding

## TL;DR

This paper introduces a high-dimensional quantum key distribution protocol using hybrid encoding of photon degrees-of-freedom, achieving higher secret key rates with practical optical components.

## Contribution

It presents a novel high-dimensional QKD scheme utilizing orbital angular momentum and multi-path modes, enhancing secret key rates over existing 2D protocols.

## Key findings

- Improved secret key rate compared to 2D protocols
- Feasible implementation with current optical technologies
- Utilization of hybrid encoding for enhanced security

## Abstract

We propose a schematic setup of quantum key distribution (QKD) with an improved secret key rate based on high-dimensional quantum states. Two degrees-of-freedom of a single photon, orbital angular momentum modes, and multi-path modes, are used to encode secret key information. Its practical implementation consists of optical elements that are within the reach of current technologies such as a multiport interferometer. We show that the proposed feasible protocol has improved the secret key rate with much sophistication compared to the previous 2-dimensional protocol known as the detector-device-independent QKD.