Scalability Analysis Of Atomic Ensemble Based Quantum Repeaters Using The NetSquid Simulator

A Quantum Internet will enable new applications that are provably impossible with classical communication alone. However, the optical fibers used to carry the quantum information are inherently lossy. To overcome the exponential losses over distance so-called quantum repeaters are needed to amplify the signal.
For the purpose of a scalability analysis we investigate the performance of different architectures using atomic-ensemble technology in a large repeater chain spanning hundreds of kilometers.
We go on to determine hardware requirements needed to cross the theoretical bound on secret key rate generation through direct transmission. By including multi-pair emission, a main source of error for these types of architectures, into our simulation we go beyond current analytical modeling of perfect photon pair sources. This allows us to assess the potential of different component technologies, such as photon sources and quantum memories, and quantify what improvements are necessary to bridge long distances.
With our simulation we provide a crucial stepping stone towards a blueprint for a pan-European quantum internet.