NMR Greenberger–Horne–Zeilinger states

We describe the creation of a Greenberger–Horne–Zeilinger (GHZ) state of the form (|00} + |111})/✓2 (three maximally entangled quantum bits) using Nuclear Magnetic Resonance (NMR). We have successfully carried out the experiment using the proton and carbon spins of trichloroethylene, and confirmed the result using state tomography. We have thus extended the space of entangled quantum states explored systematically to three quantum bits, an essential step for quantum computation.