Optimising the distribution of entanglement in quantum networks

Quantum communication is one of the most promising technologies enabled by quantum mechanics, providing the potential to perform a host of useful tasks, including quantum key distribution and coin tossing. The holy grail of quantum communication is the creation of a quantum network, where a collection of end-users can exchange quantum information over long distances. In particular, a quantum network should be able to generate entanglement between any arbitrary pair of end-users, with the ability to make a trade-off between the generation time and the quality of the entanglement. That is, one would like to find a protocol that, for a fixed quality parameter, minimises the generation time. Here, we perform a restricted, numerical optimisation to find realistic protocols that can be implemented in a near-term quantum network. By exploring the parameter-space, we improve on known protocols and discover general heuristics for the distillation of entanglement over quantum networks.