We’ve seen that to build a quantum internet, we need to be able to generate entangled states distributed across different nodes. This is a nontrivial task where hardware can be a limiting factor. In this lecture, Filip Rozpedek explains the concept of entanglement distillation, a method to filter out non-entangled states which can be generated accidentally.

Main takeaways

• Creating ideal maximally-entangled states is hard.
• Repeaters can help creating entangled states over large distances, but they also introduce noise.
• We need entanglement distillation to filter out states that are not maximally entangled.
• Entanglement distillation does not increase the amount of entanglement, just as alcohol distillation does not increase the amount of alcohol. In both distillation schemes, quantity is reduced, so that quality can be enhanced.