Four-qubit device with mixed couplings

M. Grajcar, A. Izmalkov, S. H W Van Der Ploeg, S. Linzen, T. Plecenik, Th Wagner, U. Hübner, E. Il'ichev, H. G. Meyer, A. Yu Smirnov, Peter J. Love, Alec Maassen Van Den Brink, M. H S Amin, S. Uchaikin, A. M. Zagoskin

Research output: Contribution to journalArticle

71 Citations (Scopus)


We present the first experimental results on a device with more than two superconducting qubits. The circuit consists of four three-junction flux qubits, with simultaneous ferro- and antiferromagnetic coupling implemented using shared Josephson junctions. Its response, which is dominated by the ground state, is characterized using low-frequency impedance measurement with a superconducting tank circuit coupled to the qubits. The results are found to be in excellent agreement with the quantum-mechanical predictions.

Original languageEnglish
JournalPhysical Review Letters
Issue number4
Publication statusPublished - 2006


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Grajcar, M., Izmalkov, A., Van Der Ploeg, S. H. W., Linzen, S., Plecenik, T., Wagner, T., ... Zagoskin, A. M. (2006). Four-qubit device with mixed couplings. Physical Review Letters, 96(4).