A compact entanglement distillery

TL;DR

This paper presents a resource-efficient continuous-variable entanglement distillation scheme using a fixed module with minimal quantum memories, enabling scalable quantum networks with reduced resource costs.

Contribution

It introduces a novel, resource-efficient entanglement distillation protocol requiring only linear time and constant physical resources, suitable for scalable quantum networks.

Findings

Requires only four quantum memories with up to 50% efficiency

Achieves exponential resource improvements over existing protocols

Enables feasible experimental implementation

Abstract

Large-scale quantum-correlated networks could transform technologies ranging from communications and cryptography to computation, metrology, and simulation of novel materials. Critical to achieving such quantum enhancements is distributing high-quality entanglement between distant nodes. This is made possible in the unavoidable presence of decoherence by entanglement distillation. However, current versions of this protocol are prohibitively costly in terms of resources. We introduce a new scheme for continuous-variable entanglement distillation that requires only linear temporal and constant physical or spatial resources, both of which are exponential improvements over existing protocols. Our scheme uses a fixed module - an entanglement distillery - comprising only four quantum memories of at most 50 % storage efficiency and allowing a feasible experimental implementation. Tangible quantum advantages are obtained by using non-ideal quantum memories outside their conventional role of storage. By creating, storing and processing information in the same physical space, the scheme establishes a potentially valuable technique for designing stable, scalable protocols across different quantum technologies.