NetSquid, a discrete-event simulation platform for quantum networks

In order to bring quantum networks into the real world, we would like to determine the requirements of quantum network protocols including the underlying quantum hardware. Since sufficiently detailed architecture proposals are generally too complex for mathematical analysis, it is natural to employ numerical simulation. Here, we introduce NetSquid, a generic discrete-event based platform for simulating all aspects of quantum networks and modular quantum computing systems, ranging from the physical layer hardware and the control plane all the way to the application level. We study several use cases to showcase the power of NetSquid. First, we perform a detailed physical layer simulation of repeater chains using processing nodes based on NV centres in diamond, as well as repeaters based on atomic ensembles. Second, we study the control plane of a recently introduced quantum switch beyond the analytically known regime. Use of the novel discrete-event paradigm for simulating networks allows the study of time-dependent noise in an entirely modular simulation, predicting the combined performance of physical hardware and control. Finally, we showcase Netsquid's ability to investigate large networks by simulating entanglement distribution over a chain of up to one thousand nodes using simplified physical models in less than three seconds.