Generation and robustness of quantum entanglement in spin graphs

Jan Riegelmeyer*, Dan Wignall, Marta P. Estarellas, Irene D’Amico, Timothy P. Spiller

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Entanglement is a crucial resource for quantum information processing, and so protocols to generate high-fidelity entangled states on various hardware platforms are in demand. While spin chains have been extensively studied to generate entanglement, graph structures also have such potential; however, only a few classes of graphs have been explored for this specific task. In this paper, we apply a particular coupling scheme involving two different coupling strengths to a graph of two interconnected 3 × 3 square graphs such that it effectively contains three defects. We show how this structure allows generation of a Bell state whose fidelity depends on the chosen coupling ratio. We apply partitioned graph theory in order to reduce the dimension of the graph and show that, using a reduced graph or a reduced chain, we can still simulate the same protocol with identical dynamics. Finally, we investigate how fabrication errors affect the entanglement generation protocol and how the different equivalent structures are affected, finding that for some specific coupling ratios they are extremely robust.

Original languageEnglish
Article number2
Number of pages20
JournalQuantum Information Processing
Issue number1
Publication statusPublished - 18 Dec 2020

Bibliographical note

© The Author(s) 2020


  • Partition graphs
  • Quantum computation
  • Quantum entanglement
  • Quantum information
  • Quantum networks
  • Spin graphs

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