Researchers from Hamad Bin Khalifa University’s Qatar Environment and Energy Research Institute (Qeeri), National Institute of Information and Communications Technology (NICT) of Japan, and Nippon Telegraph and Telephone Corporation (NTT) have discovered new states of interaction between atoms and light. This discovery was published this week in the high-impact journal Nature Physics.  
The indispensable technologies in modern life such as a time system measured by an atomic clock and a secure and energy-efficient communications system are based on the fundamental science of the interaction between light and matter. The absorption and emission of light from any device is explained based on the interaction of light and atoms. A fundamental question is “How strong can the interaction of light and an atom be?” This question has not been answered in spite of years of research.
Understanding the interactions between atoms and light is important to Qeeri’s research and development of new solar cells materials. In addition, this discovery may contribute to the development of quantum technologies in areas such as quantum communication, quantum simulation and computation, or quantum metrology.
Previously, Dr Sahel Ashhab, Qeeri senior scientist, performed theoretical investigations and identified desirable conditions for achieving this new state using superconducting circuits. Recently, his collaborators at NICT carried out experiments using devices fabricated jointly at the facilities of NICT and NTT. “Well-designed circuits can really go beyond what many people thought were unsurpassable limits” commented Dr Ashhab, who provided the theoretical basis and interpretation of the experiments.
Dr Ashhab said, “For technological applications, sometimes you want the strongest interactions possible. You want fast absorption and emission of light. Naturally there are limits to how strong this interaction can be, but now with artificial systems, we are able to design extremely strong interactions.”
“Forty years ago it was predicted theoretically that if you increase the strength of this interaction beyond a certain point, the atoms would form a new state, an unusual molecular state in which the atoms would bind with the photons. Scientists have since debated if this was really possible under realistic conditions. This work has answered the question. We have been able to design an electric circuit in which the circuit interacts with light in an extreme manner, creating the predicted molecular state,” he added.

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