Polarization agnostic continuous variable quantum key distribution

TL;DR

This paper presents a polarization agnostic approach to continuous-variable quantum key distribution that simplifies implementation, reduces loss, and avoids polarization correction noise by encoding in orthogonal polarization modes without active polarization management.

Contribution

It introduces a novel polarization agnostic method for Gaussian-modulated coherent state CVQKD that does not require polarization correction or monitoring both modes.

Findings

Allows secure key distribution despite polarization changes

Reduces optical loss by eliminating polarization correction components

Avoids noise associated with polarization correction algorithms

Abstract

We introduce a polarization agnostic method for Gaussian-modulated coherent state (GCMS) continuous-variable quantum key distribution (CVQKD). Due to the random and continuous nature of the GCMS protocol, Alice, the transmitter, can encode two distinct quadratures in each of two orthogonal polarization modes, such that Bob, the receiver, measures valid GCMS quadratures in a single polarization mode even when polarization changes occur during transmission. This method does not require polarization correction in the optical domain, does not require monitoring both polarization modes, reduces loss by eliminating optical components, and avoids the noise injected by polarization correction algorithms.