Entanglement Routing

Functionality Description

Entanglement routing allows a quantum network to generate long distance entanglement between two or multiple nodes. As quantum information transmissivity decays exponentially in function of the distance, quantum routers are needed to successfully establish entangled states between any nodes on a quantum network.

The main goal of entanglement routing is to develop efficient routing protocols to enable long distance entanglement.

Tags: Multi Party, Specific Task.

Use Case

• No classical analogue.

Protocols

• All the protocols within this functionality are in the Quantum Memory Network Stage.
• There are entanglement routing protocols that are specifically designed for certain network topology e.g: linear, rings (1), spheres (1), grids (2) or for networks with arbitrary topology (2, 3).
• Quantum repeater nodes have global (all the network) or local (just neighborhood) information on the state of other nodes.

Properties

• Entanglement routing assumes the presence of:
  • Classical and quantum communication physical channels.
  • Quantum repeater nodes.
• Quantum repeater nodes:
  • Contain qubits that in the short and medium term are applicable to only basic operations i.e, Bell State Measurements to pairs of neighborhood nodes allowing the Entanglement Swapping operation.
• Some protocols consider fault-tolerant operations on the nodes but other use Entanglement Distillation or Error Corrections schemes on the repeater nodes (4).

References

1. Schoute et al. Shortcuts to Quantum Network Routing (2016)
2. Pant et al. Routing entanglement in the quantum internet (2019)
3. Shi and Qian, Concurrent Entanglement Routing for Quantum Networks: Model and Designs (2020)
4. Rozpędek et al. Quantum repeaters based on concatenated bosonic and discrete-variable quantum codes (2021)

contributed by Shraddha Singh and Lucas Arenstein