# General sending-or-not-sending twin field protocol for quantum key distribution with asymmetric source parameters

## TL;DR

This paper introduces a generalized twin-field quantum key distribution protocol that accommodates asymmetric source parameters, enhancing performance in asymmetric channels and providing a security proof for this broader approach.

## Contribution

The paper presents a new SNS protocol for TFQKD with asymmetric source parameters, extending the original protocol's applicability and security proof.

## Key findings

- Improved key rate in asymmetric channels
- Security proof for the generalized protocol
- Enhanced robustness against misalignment errors

## Abstract

The sending-or-not-sending (SNS) protocol of the twin-field quantum key distribution (TFQKD) can tolerant large misalignment error and its key rate can exceed the bound of repeaterless QKD. But the original SNS protocol requires the two users to use the same source parameters. Here we propose a general protocol with asymmetric source parameters and give the security proof of this protocol. Our general protocol has a much better performance than that of the original SNS protocol when the channel of the system is asymmetric.