Heisenberg spin bus as a robust transmission line for quantum-state transfer

Sangchul Oh, Lian Ao Wu, Yun Pil Shim, Jianjia Fei, Mark Friesen, Xuedong Hu

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We study quantum-state transfer (QST) through a strongly coupled antiferromagnetic spin chain (acting as a spin bus), between weakly coupled external qubits. By treating the weak coupling as a perturbation, we find that QST is enabled specifically by the second-order terms in the perturbative expansion. We show that QST is robust against disorder in the couplings, either within the bus or to the external qubits. We find that the protocol works when the qubits are attached to any node on an even-size bus or to the antiferromagnetic nodes on an odd-size bus. The optimal time for QST is found to depend nonmonotonically on qubit separation.

Original languageEnglish
Article number022330
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number2
Publication statusPublished - 24 Aug 2011


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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