Robustness of Noisy Quantum Networks

TL;DR

This paper investigates the robustness of quantum networks with noisy quantum-repeater nodes, revealing phase transitions in connectivity loss and identifying scale-free topology as key for robustness.

Contribution

It introduces an analysis of phase transitions in noisy quantum networks and highlights the importance of scale-free topology for network robustness.

Findings

Quantum networks with noisy nodes experience abrupt connectivity loss.

Critical repeater efficiency depends on topology, size, and entanglement distribution.

Scale-free networks enhance robustness of large-scale quantum internet.

Abstract

Quantum networks are a new paradigm of complex networks, allowing us to harness networked quantum technologies and to develop a quantum internet. But how robust is a quantum network when its links and nodes start failing? We show that quantum networks based on typical noisy quantum-repeater nodes are prone to discontinuous phase transitions with respect to the random loss of operating links and nodes, abruptly compromising the connectivity of the network, and thus significantly limiting the reach of its operation. Furthermore, we determine the critical quantum-repeater efficiency necessary to avoid this catastrophic loss of connectivity as a function of the network topology, the network size, and the distribution of entanglement in the network. In particular, our results indicate that a scale-free topology is a crucial design principle to establish a robust large-scale quantum internet.