Percolation Theories for Quantum Networks

Entropy (Basel). 2023 Nov 20;25(11):1564. doi: 10.3390/e25111564.

Abstract

Quantum networks have experienced rapid advancements in both theoretical and experimental domains over the last decade, making it increasingly important to understand their large-scale features from the viewpoint of statistical physics. This review paper discusses a fundamental question: how can entanglement be effectively and indirectly (e.g., through intermediate nodes) distributed between distant nodes in an imperfect quantum network, where the connections are only partially entangled and subject to quantum noise? We survey recent studies addressing this issue by drawing exact or approximate mappings to percolation theory, a branch of statistical physics centered on network connectivity. Notably, we show that the classical percolation frameworks do not uniquely define the network's indirect connectivity. This realization leads to the emergence of an alternative theory called "concurrence percolation", which uncovers a previously unrecognized quantum advantage that emerges at large scales, suggesting that quantum networks are more resilient than initially assumed within classical percolation contexts, offering refreshing insights into future quantum network design.

Keywords: critical phenomena; entanglement distribution; hypergraph; networks of networks; percolation; quantum network.

Publication types

  • Review

Grants and funding

X.H. and G.D. weresupported by grants from the National Natural Science Foundation of China (Grants 62373169, 61973143). Y.T. is funded by the Wallenberg Initiative on Networks and Quantum Information (WINQ). R.L. acknowledges support from the EPSRC Grants EP/V013068/1 and EP/V03474X/1, as well from the International Exchanges IEC\NSFC\201180 of the Royal Society. J.G. acknowledges the support of National Science Foundation under Grant No. 2047488. S.H. thanks the EU H2020 DIT4Tram (Grant number 953783) and the Horizon Europe grant OMINO (grant number 101086321).