Seminar: Professor Wolfgang Dür from Universität Innsbruck

Entanglement-based quantum networks

We consider entanglement-based quantum networks, where pre-shared multipartite entangled states serve as a resource to fulfill network requests on demand. This offers new possibilities and features such as speeding up network requests, and network optimization independent of the underlying physical structure. We identify suitable resource states shared between network devices that can be stored, and then modified by local means to generate desired output states. We show how to design and optimize such entanglement-based networks, and study their performance under noise. Finally, we discuss how to make quantum networks genuine quantum by providing them with the possibility of handling superposed tasks. This allows one e.g. to prepare superposition of different target states, or to send information among a superposition of different paths. We discuss applications of this principle in networks, but also as a tool in quantum computation where performing gates and whole circuits in coherent superposition leads to noise reduction.