Researchers from the Center for Quantum Nanoscience (QNS) within the Institute for Basic Science (IBS) at Ewha Womans University made a major scientific breakthrough by performing the world's smallest magnetic resonance imaging (MRI) on single atoms.
QNS scientists, in collaboration with international colleagues used their new technique to visualize the magnetic field of single atoms.
MRIs are usually conducted in hospitals as a part of imaging for diagnostics and detect the density of spins—the fundamental magnets in electrons and protons in the human body. Published in the journal Nature Physics the new findings go on to show this process is now also possible for an individual atom on a surface.
The research team used a scanning tunneling microscope, which consists of an atomically sharp metal tip that allows researchers to image and probe single atoms by scanning the tip across the surface.
The two elements investigated in the work were iron and titanium, which are both magnetic. The atoms were readily visible in the microscope, through precise preparation and the researchers then used the used the microscope's tip like an MRI machine to map the three-dimensional magnetic field created by the atoms with unprecedented resolution.
Speaking about it, lead author Dr. Philip Willke of QNS said that the magnetic interaction they measured depended on the properties of both spins, the one on the tip and the one on the sample. “For example, the signal that we see for iron atoms is vastly different from that for titanium atoms. This allows us to distinguish different kinds of atoms by their magnetic field signature, and makes our technique very powerful,” he said.
The ability to analyze the magnetic structure on the nanoscale can help researchers to develop new materials and drugs.