Daily supervisor: Álvaro G. Iñesta (a.gomezinesta@tudelft.nl).
Project supervisor: Stephanie Wehner.

Quantum networks are expected to enable multi-party applications that are provably impossible by using only classical information. Most of these applications consume shared entanglement as a basic resource. Entanglement distribution protocols are used to generate and share multipartite entanglement among remote parties. In particular, protocols for continuous distribution of entanglement (CD protocols) continuously distribute entangled states among the nodes. These entangled states can be consumed by the nodes whenever they need them, allowing background applications to continuously operate and consume entanglement in the background.

Here, we focus on the performance evaluation of CD protocols. Specifically, we consider protocols whose goal is to supply remote nodes with shared bipartite entanglement (see Figure 1 for a graphical intuition). A novel approach to evaluate the performance of CD protocols was proposed in [1]. In this project, our main goal is to use the performance metrics proposed in [1] to guide the design of real fiber networks for entanglement distribution.

Figure 1: Illustration of a seven-node quantum network. Nodes are represented as gray circles and physical channels are represented as gray lines. Bipartite entanglement is represented as a black line connecting two occupied qubits (small black circles). The physical topology is static, while the entanglement is continuously created, discarded, and consumed.

Goals of the Project:

• Investigate real fiber networks that can be used for classical and quantum communication simultaneously and describe them mathematically.
• Evaluate the performance of CD protocols in such networks and understand the role of the topology in protocol performance.
• Extract conclusions to guide the design of future fiber networks to be used for classical and quantum communication.

Requirements:

At the start of the project, the student must be familiar with Python and git (software for version control) and have a solid background on probability theory. Knowledge in graph theory, Markov chains, and performance analysis is appreciated but not required.

References:

[1] Álvaro G. Iñesta and Stephanie Wehner. Performance metrics for the continuous distribu- tion of entanglement in multi-user quantum networks. arXiv preprint arXiv:2307.01406, 2023.