Scientists discover how metal can become magnetic with light

A new method for making non-magnetic metals magnetic has been developed by a group of researchers from the University of Copenhagen and Nanyang Technology University, Singapore. According to the press release, the process of using laser light can also be used to equip many materials with new properties.

Researchers have discovered that when they stimulate a metal through a certain process with laser light, its structure can transform and acquire new properties. The study was explained by Mark Rudner, a researcher at the Niels Bohr Institute of the Danish University: “We have been studying for several years how to transform the properties of a substance by emitting it with certain types of light. The novelty is that not only can we change properties with the help of light, but we can also change the material from the inside out and create a new phase with completely new properties. For example, a non-magnetic metal can suddenly become a magnet.”

According to researchers, the electrical currents circulating in the metal essentially appear spontaneously when the metal itself is irradiated with linear polarised light. What changes are the plasmons, a kind of electronic wave, present in the metal that begins to rotate clockwise or counterclockwise and change the electronic structure of the material, causing instability in the direction of the autorotation that makes the metal magnetic.

The study was published in Nature Physics.


See also:

https://news.ku.dk/all_news/2019/09/quantum-alchemy-researchers-use-laser-light-to-transform-metal-into-magnet/

https://www.nature.com/articles/s41567-019-0578-5

Image source:

https://www.thoughtco.com/thmb/0tfhJpGmwJZ7XHqMyzxLxs2r2HE=/2110×1421/filters:fill(auto,1)/illustration-of-a-horseshoe-magnet-s-attractive-power-172221336-5c3feb6646e0fb00010fbb39.jpg