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Quantum repeater networks that allow long-distance entanglement distribution will be the backbone of distributed quantum information processing. In this paper we explore entanglement distribution using quantum repeaters with optimized…

Quantitative characterization of two-qubit entanglement purification protocols is introduced. Our approach is based on the concurrence and the hit-and-run algorithm applied to the convex set of all two-qubit states. We demonstrate that…

Quantum Physics · Physics 2024-09-04 Francesco Preti , József Zsolt Bernád

We investigate efficient entanglement purification through double selection process. This method works with higher noise thresholds for the communication channels and local operations, and achieves higher fidelity of purified states.…

Quantum Physics · Physics 2015-05-13 Keisuke Fujii , Katsuji Yamamoto

We introduce entanglement purification protocols for d-level systems (qudits) with improved efficiency as compared to previous protocols. While we focus on protocols for bipartite systems, we also propose generalizations to multi-partite…

Quantum Physics · Physics 2018-10-17 Jorge Miguel-Ramiro , Wolfgang Dür

A quantum network is expected to enhance distributed quantum computing and quantum communication over a long distance while providing unconditional security. As quantum entanglement is essential for a quantum network, major issues from…

Quantum networks rely on high fidelity entangled pairs distributed to nodes, but maintaining their fidelity is challenged by environmental decoherence during storage. Entanglement purification is used to restore fidelity, but the idle…

Networking and Internet Architecture · Computer Science 2025-09-05 Vivek Vasan , Alexander Nico-Katz , Boulat A. Bash , Daniel C. Kilper , Marco Ruffini

Bipartite entanglement purification is the conversion of copies of weakly entangled pairs shared between two separated parties into a smaller number of strongly entangled shared pairs using only local operations and classical communication.…

Quantum Physics · Physics 2025-11-14 Matthew Barber , Stefano Pirandola

We present the convergence study of a recurrence entanglement purification protocol using arbitrary two-qubit initial states. The protocol is based on a rank two projector in the Bell basis which serves as a two-qubit operation replacing…

Quantum Physics · Physics 2016-11-23 Juan Mauricio Torres , József Zsolt Bernád

Since its discovery, the quantum entanglement becomes a promising resource in quantum communication and computation. However, the entanglement is fragile due to the presence of noise in quantum channels. Entanglement purification is a…

Quantum Physics · Physics 2023-04-26 Peishun Yan , Lan Zhou , Wei Zhong , Yubo Sheng

Entanglement distribution is a core mechanism for the future quantum Internet. The quantum world is, however, a faulty environment. Hence, successful entanglement swapping is error-prone. The occurrence of quantum state errors can be…

Quantum Physics · Physics 2023-02-28 Michel Barbeau , Joaquin Garcia-Alfaro , Evangelos Kranakis

Long-distance quantum communication requires reliable entanglement distribution, but direct generation with protocols such as Barrett--Kok suffers from exponentially decreasing success probability with distance, making it impractical over…

Quantum Physics · Physics 2025-10-10 Wenhan Li , Shiyu Zhang

Quantum networks will be able to service consumers with long-distance entanglement by use of quantum repeaters that generate Bell pairs (or links) with their neighbors, iid with probability $p$ and perform Bell State Measurements (BSMs) on…

The degradation of entanglement in quantum memories due to decoherence is a critical challenge for scalable quantum networks. We present an entanglement distillation protocol based on the [[4,2,2]] quantum error-detecting code, deriving…

Quantum Physics · Physics 2025-09-09 Huidan Zheng , Gunsik Min , Ilkwon Sohn , Jun Heo

Entanglement purification is to distill high-quality entangled states from low-quality entangled states. It is a key step in quantum repeaters, determines the efficiency and communication rates of quantum communication protocols, and is…

Quantum Physics · Physics 2022-03-21 Cen-Xiao Huang , Xiao-Min Hu1 , Bi-Heng Liu , Lan Zhou , Yu-Bo Sheng , Chuan-Feng Li , Guang-Can Guo

Superdense Coding is a cornerstone in secure quantum communication, exploiting pre-shared entanglement to encode two classical bits within a single qubit. However, noise and decoherence deteriorate entanglement quality, restricting both…

Quantum Physics · Physics 2025-04-18 Syed Emad Uddin Shubha , Tasnuva Farheen

This work introduces a compact framework for analyzing asynchronous entanglement distribution protocols under realistic error models. We focus on two contemporary protocols: sequential, where entanglement is established one node at a time,…

Quantum Physics · Physics 2025-11-13 Emma Hughes , William Munizzi , Prineha Narang

Quantum communication enables secure information transmission and entanglement distribution, but these tasks are fundamentally limited by the capacities of quantum channels. While quantum repeaters can mitigate losses and noise,…

Quantum Physics · Physics 2026-02-02 Ozlem Erkilic , Matthew S. Winnel , Aritra Das , Sebastian Kish , Ping Koy Lam , Jie Zhao , Syed M. Assad

Quantum data-center networks must distribute entanglement between QPUs over paths whose length grows with system scale, but each entanglement-swapping step reduces the quality of the raw end-to-end state. Topology, multiplexing, and…

Entangled states shared among distant nodes are frequently used in quantum network applications. When quantum resources are abundant, entangled states can be continuously distributed across the network, allowing nodes to consume them…

Quantum Physics · Physics 2024-02-01 Álvaro G. Iñesta , Stephanie Wehner

How to efficiently distribute entanglement over large-scale quantum networks is still an open problem that greatly depends on the technology considered. In this work, we consider quantum networks where each link is characterized by a…

Quantum Physics · Physics 2024-09-10 Bruno C. Coutinho , Raul Monteiro , Luís Bugalho , Francisco A. Monteiro