Testing quantum contextuality with macroscopic superconducting circuits

We propose an experimental procedure to macroscopically test the Kochen-Specker theorem with superconducting qubits. This theorem, which has been experimentally tested with single photons and neutrons, elucidates the conflict between quantum mechanics and noncontextual hidden variable theories. Two Josephson charge qubits can be controllably coupled by using a two-level data bus built with a phase qubit. Then, by performing joint nondestructive quantum measurements of two distinct qubits, we show that the proposed circuits could demonstrate quantum contextuality at a macroscopic level.