It's not that difficult to find examples of fractals in the natural world. So it may come as a surprise that, until now, there still remained some places these endlessly repeating geometrical patterns have never been seen.
Physicists from MIT recently provided the first known example of a fractal arrangement in a quantum material.
According to Science Alert, the patterns were seen in an unexpected distribution of magnetic units called 'domains', that develop in a compound named neodymium nickel oxide, which is a rare earth metal with unique properties.
Getting a better understanding of those domains and their patterns could lead to new ways of storing and protecting digital information.
This is pretty cool, as neodymium nickel oxide, or NdNiO3, is strange stuff.
If you pull a piece out of your pocket and zap it with a current, it will conduct pretty easily. If you drop it into liquid nitrogen so that it falls below a critical temperature of about minus 123 degrees Celsius (minus 189 Fahrenheit), it'll shut up shop and become an insulator.
Like most of ferromagnetic materials, atoms in neodymium nickel oxide team up as tiny clumps of magnetically oriented particles called domains.
Domains come in a range of sizes and arrangements, depending on quantum interactions between electrons and their atoms under certain conditions. But how they emerge in neodymium nickel oxide, given its nature as a conductor moonlighting as an insulator, was the big question.
That particular solution was as old as it is novel – they used the very same technology many old fashioned lighthouses employ to channel light into a tight beam.
Fresnel lenses are stacked layers of a transparent material with ridges which redirect electromagnetic radiation. Though the lenses in lighthouses can be meters across, the ones Comin and his team developed were just 150 microns wide.
The result was an X-ray beam small enough to detect the fine-scale of magnetic domains across a thin film of lab-grown neodymium nickel oxide.
Most of these domains were tiny. Scattered among them were some bigger ones. When the numbers were crunched and a map drawn, though, the distribution of bigger domains among a sea of tiny ones looked uncannily similar in spite of what scale you were using.
Neodymium nickel oxide will certainly be part of the big picture of future electronics.
The research was published in Nature Communications.