We propose a coupling scheme, where two or more flux qubits with different eigenfrequencies share Josephson junctions with a coupler loop devoid of its own quantum dynamics. Switchable two-qubit coupling is realized by tuning the frequency of the AC magnetic flux through the coupler to a combination frequency of two of the qubits. The coupling allows any or all of the qubits to be simultaneously at the degeneracy point and can change sign.
@article{arxiv.cond-mat/0605484,
title = {Switchable resonant coupling of flux qubits},
author = {M. Grajcar and Yu-xi Liu and Franco Nori and A. M. Zagoskin},
journal= {arXiv preprint arXiv:cond-mat/0605484},
year = {2009}
}
Comments
REVTeX 4, 4 pages, 2 figures, v2: reference added, v3: final version published in Phys. Rev. B