On the Fidelity Distribution of Purified Link-level Entanglements

Elsayed, Karim S; KhudaBukhsh, Wasiur R; Rizk, Amr

Abstract

The first step for entanglement distribution among quantum communication nodes is to generate link-level Ein-stein-Podolsky-Rosen (EPR) pairs between adjacent communication nodes. EPR pairs may be continuously generated and stored in a few quantum memories to be ready for utilization by quantum applications. A major challenge is that qubits suffer from unavoidable noise due to their interaction with the environment, which is called decoherence. This decoherence results in the known exponential decay model of the fidelity of the qubits with time, thus, limiting the lifetime of a qubit in a quantum memory and the performance of quantum applications. In this paper, we evaluate the fidelity of the stored EPR pairs under two opposite dynamical and probabilistic phenomena, first, the aforementioned decoherence and second purification, i.e. an operation to improve the fidelity of an EPR pair at the expense of sacrificing another EPR pair. Instead of applying the purification as soon as two EPR pairs are generated, we introduce a Purification scheme Beyond the Generation time (PBG) of two EPR pairs. We use discrete time Markov chain (DTMC) approach to analytically show the probability distribution of the fidelity of stored link-level EPR pairs in a system with two quantum memories at each node allowing a maximum of two stored EPR pairs. In addition, we apply a PBG scheme that purifies the two stored EPR pairs upon the generation of an additional one. We finally provide numerical evaluations of the analytical approach and show the fidelity-rate trade-off of the considered purification scheme.

Citation

Elsayed, K. S., KhudaBukhsh, W. R., & Rizk, A. (2024, June). On the Fidelity Distribution of Purified Link-level Entanglements. Presented at ICC 2024 - IEEE International Conference on Communications, Denver, CO, USA

• Presentation Conference Type: Edited Proceedings
• Conference Name: ICC 2024 - IEEE International Conference on Communications
• Start Date: Jun 9, 2024
• End Date: Jun 13, 2024
• Online Publication Date: Aug 20, 2024
• Publication Date: Jun 9, 2024
• Deposit Date: Aug 25, 2024
• Publicly Available Date: Oct 9, 2024
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Pages: 485-490
• Book Title: ICC 2024-IEEE International Conference on Communications
• DOI: https://doi.org/10.1109/ICC51166.2024.10622822
• Public URL: https://nottingham-repository.worktribe.com/output/38893702
• Publisher URL: https://ieeexplore.ieee.org/document/10622822