Quantum synchronisation and clustering in chiral networks

We study the emergence of synchronisation in a chiral network of harmonic oscillators. The network consists of a set of locally incoherently pumped harmonic oscillators coupled pairwise in cascade with travelling field modes. Such cascaded coupling leads to feedback-less dissipative interaction between the harmonic oscillators of the pair which can be described in terms of an effective pairwise hamiltonian a collective pairwise decay. The network is described mathematically in terms of a directed graph. By analysing geometries of increasing complexity we show how the onset of synchronisation depends strongly on the network topology, with the emergence of synchronised communities in the case of complex networks. The quantum nature of the non local correlation between network nodes is assessed.
SL and GMP acknowledge support by MUR under PRIN Project No. 2017 SRN-BRK QUSHIP, RZ acknowledges support from MINECO/AEI/FEDER through projects QUARESC PID2019-109094GB-C21 and the María de Maeztu Program for Units of Excellence in R&D (MDM-2017-0711).