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

Journal Article · Mon Aug 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.022330· OSTI ID:22068523

Oh, Sangchul; Xuedong, Hu ^[1]; Lianao, Wu ^[2]; Shim, Yun-Pil; Fei, Jianjia; Friesen, Mark ^[3]

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1. Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260-1500 (United States)
2. Department of Theoretical Physics and History of Science, Basque Country University (EHU/UPV), P.O. Box 644, E-48080 Bilbao (Spain)
3. Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

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.

• OSTI ID: 22068523
• Journal Information: Physical Review. A, Vol. 84, Issue 2; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTIFERROMAGNETISM
COUPLING
HEISENBERG MODEL
PERTURBATION THEORY
QUANTUM STATES
QUBITS
SPIN