Quantum Computation and Information Seminar 

02/10/2019, 12:00 — 13:00 — Seminar room (2.8.3), Physics Building
Kaushik Chakraborty, TU Delft

Distributed Routing in a Quantum Internet

In this presentation, I will talk about routing algorithms which can be used for distributing entanglement in a quantum network with noisy quantum devices. First, we consider two different models for the operation of such a quantum network. One of them is called the continuous model and the other one is called the on-demand model. In the continuous model, each node in the network continuously generates EPR pairs in the background with some of the other nodes in the network and store them into a noisy quantum memory. This can in principle allows the rapid creation of entanglement between more distant nodes using already pre-generated EPR pairs. In the on-demand model, entanglement production does not commence before a request is made.

Both of the models have their advantages and disadvantages. For example, in the continuous model one can reduce the diameter of the network by pre-sharing longer links in the network. In this talk, I will give one example of the pre-sharing strategy which uses some ideas from classical complex network theory. This makes the continuous model very efficient. However, routing in the continuous model is a challenging task. The reason is that all of the pre-shared links are temporary in nature. A pre-shared EPR-pair is being consumed after one round of teleportation or it decoheres and eventually becomes unusable after a certain period of time. This makes the network topology in the continuous model dynamic. In this talk, I will mention two distributed greedy routing algorithms and compare their performances in both continuous and on-demand model.