Direct Josephson coupling between superconducting flux qubits

M. Grajcar; A. Izmalkov; S. H. W. van der Ploeg; S. Linzen; E. Il'ichev; Th. Wagner; U. Hubner; H. -G. Meyer; Alec Maassen van den Brink; S. Uchaikin; A. M. Zagoskin

doi:10.1103/physrevb.72.020503

arXiv · cond-mat/0501085

Direct Josephson coupling between superconducting flux qubits

M. Grajcar·A. Izmalkov·S. H. W. van der Ploeg·S. Linzen·E. Il'ichev·Th. Wagner·U. Hubner·H. -G. Meyer·Alec Maassen van den Brink·S. Uchaikin·A. M. Zagoskin

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Abstract

We have demonstrated strong antiferromagnetic coupling between two three-junction flux qubits based on a shared Josephson junction, and therefore not limited by the small inductances of the qubit loops. The coupling sign and magnitude were measured by coupling the system to a high-quality superconducting tank circuit. Design modifications allowing to continuously tune the coupling strength and/or make the coupling ferromagnetic are discussed.

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M. Grajcar, A. Izmalkov, S. H. W. van der Ploeg, S. Linzen, E. Il'ichev, Th. Wagner, U. Hubner, H. -G. Meyer, Alec Maassen van den Brink, S. Uchaikin, A. M. Zagoskin. 2005-03-29. Direct Josephson coupling between superconducting flux qubits. https://doi.org/10.1103/physrevb.72.020503

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