# Semihierarchical quantum repeaters based on moderate lifetime quantum memories

## TL;DR

This paper introduces a semi-hierarchical quantum repeater protocol that enhances entanglement distribution efficiency and reduces memory time requirements, facilitating scalable large-scale quantum networks with current technology.

## Contribution

The proposed protocol offers a practical, scalable approach for quantum repeaters that operates efficiently with moderate lifetime quantum memories and fixed elementary link distances.

## Key findings

- Improved entanglement distribution rate.
- Reduced quantum memory time requirements.
- Suitable for large-scale quantum networks.

## Abstract

The construction of large-scale quantum networks relies on the development of practical quantum repeaters. Many approaches have been proposed with the goal of outperforming the direct transmission of photons, but most of them are inefficient or difficult to implement with current technology. Here, we present a protocol that uses a semi-hierarchical structure to improve the entanglement distribution rate while reducing the requirement of memory time to a range of tens of milliseconds. This protocol can be implemented with a fixed distance of elementary links and fixed requirements on quantum memories, which are independent of the total distance. This configuration is especially suitable for scalable applications in large-scale quantum networks.