A network-ready random-access qubits memory

TL;DR

This paper demonstrates a multi-qubit photonic memory using two rubidium atoms in an optical cavity, achieving high efficiency and coherence, advancing quantum networking capabilities.

Contribution

It introduces a random-access multi-qubit photonic memory with no cross talk and sustained performance over multiple operations, suitable for quantum internet nodes.

Findings

Memory supports over ten photonic qubits without cross talk.

Achieves a 26% write-read efficiency.

Coherence time approaches 1 millisecond.

Abstract

Photonic qubits memories are essential ingredients of numerous quantum networking protocols. The ideal situation features quantum computing nodes that are efficiently connected to quantum communication channels via quantum interfaces. The nodes contain a set of long-lived matter qubits, the channels support the propagation of light qubits, and the interface couples light and matter qubits. Towards this vision, we here demonstrate a random-access multi-qubit write-read memory for photons using two rubidium atoms coupled to the same mode of an optical cavity, a setup which is known to feature quantum computing capabilities. We test the memory with more than ten independent photonic qubits, observe no noticeable cross talk, and find no need for re-initialization even after ten write-read attempts. The combined write-read efficiency is 26% and the coherence time approaches 1ms. With these features, the node constitutes a promising building block for a quantum repeater and ultimately a quantum internet.