A crystal lattice made of light traps atoms in several bilayer sheets allowed scientists to see competition between magnetic orders for the first time, which they say promises new insights into the quantum qualities of two-dimensional materials. Illustration by Marcell Gall, Nicola Wurz et al./Nature
Jan. 6 (UPI) -- For the first time, scientists have observed competition between magnetic orders from coupled sheets of atoms. The observations, described Wednesday in the journal Nature, promise new insights into the quantum qualities of two-dimensional materials.
Ever since a pair of British researchers were awarded the Nobel Prize in 2010 for the discovery of graphene, material scientists, electrical engineers, quantum physicists and others have been fascinated by the unusual electromagnetic qualities of 2D materials -- characteristics that could only be explained by the laws of quantum mechanics.
In its pure 2D form, graphene consists of a single layer of carbon atoms arranged in a lattice pattern. The material has served as the subject of thousands of scientific papers published over the last decade.
Though many of graphene's quantum properties have been thoroughly described, the precise origins of many of these qualities -- the quantum mechanics behind the phenomena -- remain a mystery.
For the new research, scientists used quantum simulators to model the interactions of several quantum particles.
The simulators feature a collection of ultra cold atoms. Cooled by lasers and magnetic fields, each atom in a quantum simulator measures just a millionth of a degree above absolute zero.
When suspended in standing waves generated by superimposing laser beams, or optical lattices, the ultra cold atoms simulate the behavior of solid state electrons.
Researchers were able to use the novel simulator to measure the magnetic correlations between two coupled layers of a crystal lattice.
"Via the strength of this coupling, we were able to rotate the direction in which magnetism forms by 90 degrees -- without changing the material in any other way," researchers at the University of Bonn in Germany, Nicola Wurz and Marcell Gall, wrote in a news release.
Thanks to the observational breakthrough, scientists can now study the behavior of magnetic forces in 2D materials at nanoscale.
The research could help scientists make more accurate predictions about the quantum properties and electromagnetic behavior of new types of nano materials.
"Our work will enable the exploration of further properties of coupled-layer Hubbard models, such as theoretically predicted superconducting pairing mechanisms," researchers wrote.