Coherence and synchronization in complex quantum networks
Nov. 28, 2018
The transport and storage of quantum information both within and across complex quantum networks is crucially affected by the presence of environment-induced noise. Interaction with the environment deteriorates the quantum properties initially present and this is important both for the design of quantum communication networks and for the understanding and control of light capture in complex quantum systems. A team led by IFISC researchers (UIB-CSIC) has predicted that these complex networks can host protected modes of the environment.
The article, published in Quantum Information, shows that complex quantum networks, both random and small-world, can support localized vibrations undisturbed by collective dissipation. Based on results in ordered systems with symmetries in the interaction of the system and the environment, scientists have extended this approach to complex networks. Depending on the topological characteristics of the network, the abundance with which some units of the system are perfectly protected from the negative influence of the environment varies. With the appropriate topology and a sufficiently high degree of similarity, these states can be made free of decoherence (when a physical system ceases to exhibit quantum effects and starts to exhibit classical physics behavior) for long periods of time. In addition, the study predicts the emergence of quantum synchronization between network nodes in a model for interaction with the environment in which all nodes dissipate in a common environment. Researchers have been able to characterize vibrations in the system that are immune to dissipation using numerical and analytical methods where possible.
Albert Cabot, Fernando Galve, Víctor M. Eguíluz, Konstantin Klemm, Sabrina Maniscalco and Roberta Zambrini. Unveiling noises clusters in complex quantum networks. Quantum Information. DOI: 10.1038/s41534-018-0108-9
