Hybrid Single-Ion Atomic-Ensemble Node for High-Rate Remote Entanglement Generation

TL;DR

This paper proposes a hybrid quantum network architecture combining trapped-ion nodes and ensemble-based memories to enhance high-rate remote entanglement generation over long distances.

Contribution

It introduces a method to match photon bandwidths from different quantum systems, enabling parallel probabilistic entanglement tasks for faster quantum communication.

Findings

Achieved bandwidth matching between different quantum systems.

Enabled parallel execution of entanglement generation tasks.

Significantly increased speed of ion-ion entanglement over long distances.

Abstract

Different quantum systems possess different favorable qualities. On the one hand, ensemble-based quantum memories are suited for fast multiplexed long-range entanglement generation. On the other hand, single-atomic systems provide access to gates for processing of information. Both of those can provide advantages for high-rate entanglement generation within quantum networks. We develop a hybrid architecture that takes advantage of these properties by combining trapped-ion nodes and nodes comprised of spontaneous parametric down conversion photon pair sources and absorptive memories based on rare-earth ion ensembles. To this end, we solve the central challenge of matching the different bandwidths of photons emitted by those systems in an initial entanglement-generation step. This enables the parallel execution of multiple probabilistic tasks in the initial stage. As a particular example, we show that our approach can lead to a significant speed-up for the fundamental task of creating ion-ion entanglement over hundreds of kilometers in a quantum network.