A Universal Quantum Information Preserving Photonic Switch for Scalable Quantum Networks

TL;DR

This paper introduces a universal quantum switch capable of dynamically routing quantum information with minimal decoherence, enabling scalable and reconfigurable quantum networks.

Contribution

It presents the first experimental demonstration of a high-speed, multi-node quantum switch supporting dynamic entanglement distribution and modality conversion.

Findings

Achieved robust switching with ≤4% decoherence using thermo-optic and electro-optic methods.

Demonstrated high-speed reconfiguration up to 1 GHz.

Supported arbitrary entangled states at 1 MHz.

Abstract

Quantum networks are a keystone of the quantum internet. However, existing implementations remain largely confined to static point-to-point links due to the absence of a switching paradigm capable of dynamically routing fragile quantum entanglement without introducing decoherence. Here, we propose the Universal Quantum Switch, a foundational building block allowing on-demand, non-blocking, and encoding-agnostic routing of quantum information, as well as seamless modality conversion between disparate quantum platforms. We develop a prototype in thin-film lithium niobate and experimentally demonstrate robust switching with $\le 4\%$ decoherence via thermo-optic modulation and high-speed electro-optic switching of arbitrary entangled states at 1 MHz. Moreover, we show that our platform can support reconfiguration speeds up to 1 GHz. To our knowledge, this work represents the first demonstration of multi-node dynamic entanglement distribution at these speeds. Complementing these experimental results, we project the architecture's scalability, showing dimension-independent decoherence, and provide a scalable, interoperable building block for heterogeneous quantum network fabrics.