  Going beyond the entanglement of microscopic objects (such as photons, spins,
and ions), here we propose an efficient approach to produce and control the
quantum entanglement of three macroscopic coupled superconducting qubits. By
conditionally rotating, one by one, selected Josephson charge qubits, we show
that their Greenberger-Horne-Zeilinger (GHZ) entangled states can be
deterministically generated. The existence of GHZ correlations between these
qubits could be experimentally demonstrated by effective single-qubit
operations followed by high-fidelity single-shot readouts. The possibility of
using the prepared GHZ correlations to test the macroscopic conflict between
the noncommutativity of quantum mechanics and the commutativity of classical
physics is also discussed.
