Major discovery in controlling quantum states of single atoms

Researchers at the Center for Quantum Nanoscience within the Institute for Basic Science (IBS) have made a major breakthrough in controlling the quantum properties of single atoms. In an international collaboration with IBM Research in San Jose, California, using advanced techniques, the scientists identified which mechanisms destroy the quantum properties of individual atoms by manipulating the magnetic state of a single iron atom on a thin insulator. Using a scanning tunneling microscope with an atomically sharp metal tip, they were able to image individual iron atoms and measure and control the time that they maintain their quantum behavior.

Their findings, published in the journal Science Advances, show that the loss in quantum state superposition is mainly caused by nearby electrons that the researchers precisely injected into the iron atom.

"We found that almost every electron destroys the quantum state," explains Dr. Philip Willke, first author of the study. "In addition, we found that nearby fluctuating magnets had a similar negative impact. While our experiments decreased the state of superposition on purpose, it also gave us valuable clues on how to improve the atoms' quantum states."

Andreas Heinrich, Director of the IBS Center for Quantum Nanoscience, said, "Understanding these destructive interactions allows us to avoid them in future experiments and improve the performance of magnetic quantum sensors that, in this case, only consist of a single atom."