Why making quantum repeaters is hard
Current state-of-the-art devices allow for a quantum connection of up to about 100km. Going further than that becomes exponentially more challenging, and we need some workaround to create a quantum network over larger distances. One of those workarounds is trusted repeaters, which have already been constructed in practice. Quantum repeaters would be even better, but those are very hard actually to make! In this video, David Elkouss gives an overview of what all these things are and why they are so hard.
Prerequisite knowledge
- Quantum Key Distribution
- Entanglement
- Teleportation
- Optical fibers
Further thinking
We can describe a lot of the procedures and principles described above as quantum circuits.
- What would the ‘entanglement swap’ performed by a quantum repeater look like as a circuit?
- How could we deal with the noise that might be added by the communication channel?
- What would entanglement distillation look like as a circuit?