# Continuous variable quantum key distribution with multi-mode signals for noisy detectors

## TL;DR

This paper introduces a multi-mode CV-QKD scheme that maintains high bandwidth and security despite noisy detectors, by enhancing shot noise sensitivity and reducing electronic noise, demonstrated through simulation.

## Contribution

It presents a novel multi-mode Gaussian modulated CV-QKD protocol that improves performance with noisy detectors, enabling higher secure key rates and distances.

## Key findings

- Enhanced shotnoise sensitivity in multi-mode systems
- Reduced electronic noise variance of the receiver
- Increased secure key rate with more signal modes

## Abstract

This paper proposes a multi-mode Gaussian modulated continuous variable quantum key distribution (CV-QKD) scheme able to operate at high bandwidth despite using conventional noisy, coherent detectors. We demonstrate enhancement in shotnoise sensitivity as well as reduction in the electronic noise variance of the coherent receiver of the multi-mode CV-QKD system. A proof-of-concept simulation is presented using multiple modes; this demonstrates an increase in signal-to-noise ratio and secure key rate at various transmission distances with increasing signal modes.