Princeton researchers have confirmed a theory first put forward in 1929 by the Nobel laureate Felix Bloch, who theorized that certain kinds of materials, when drawn down to a very low electron density, would spontaneously magnetize.
Princeton researchers have confirmed a theory first put forward in 1929 by the Nobel laureate Felix Bloch, who theorized that certain kinds of materials, when drawn down to a very low electron density, would spontaneously magnetize.
In the study, published August 17 in Nature Physics, researchers led by Mansour Shayegan, professor of electrical engineering, used an ultra-pure semiconductor to explore what happens to electrons as they become less densely packed in a two-dimensional space, a plane between two solids that is only one particle deep.
As the team slowly reduced the material's electron density, they first saw an expected result: its magnetic properties became weaker until they disappeared altogether. While very few systems have explored electron density at this level, the mathematics made sense of the results to that point. The researchers had surpassed a critical threshold. But because they were working with a rare material system that allowed them to study these effects at even lower densities, they decided to keep going and push the experiment to its physical brink. What happened next came as a surprise.
Read more at Princeton University
Image: Electrical engineering researchers discovered a new magnetic phenomenon, confirming a nearly 100-year-old theory first put forward by the Nobel laureate Felix Bloch. Microscopy images courtesy of the researchers.
