Synthetic diamond maker Element Six, working in collaboration with Delft University of Technology in the Netherlands, entangled quantum bits, or qubits, in two synthetic diamonds separated in space — a step toward enabling new, quantum-based networks and computers, the company said. The collaboration used two synthetic diamonds of millimeter-size grown by Element Six through chemical vapor deposition (CVD). The diamonds were engineered to contain a particular defect that can be manipulated using light and microwaves. The light emitted from the defect, known as a nitrogen vacancy (NV) defect, allows the quantum properties of the defect to be ‘read out’ using a microscope. Two synthetic diamonds, nano-engineered by Element Six, achieve quantum entanglement and drive advancements in information technologies and fundamental physics. Courtesy of Element Six. By forming small lenses around the NV defect and carefully tuning the light emitted through electric fields, the Delft team made the two NV defects emit indistinguishable photons that contained the defects’ quantum information. Further manipulation allowed the quantum-mechanical entanglement of the two defects. Element Six, a member of the De Beers Group, collaborates with a number of universities. The company said the findings demonstrate its ability to control a single atom-like defect in the diamond lattice at the parts-per-trillion level, and it is the first time that qubits in two separated diamonds have been entangled and subsequently shown to behave as a single particle. “This is an important achievement that will help us not only create a quantum network to process information, but ultimately a future quantum computer,” said TU Delft professor Ronald Hanson. “The field of synthetic diamond science is moving very quickly, requiring us to develop CVD techniques that produce exceptionally pure synthetic diamond material at nano-engineering levels,” said Adrian Wilson, head of Element Six Technologies. The findings were published in Nature (http://dx.doi.org/10.1038/nature12016). For more information, visit: www.e6.com or www.tudelft.nl/en/