Researchers at the Zurich Federal Institute of Technology, ETH Zurich, in Switzerland, have discovered a new type of magnetism in “moiré pattern” materials. The material is created by stacking two-dimensional sheets of molybdenum diselenide and tungsten disulfide.
The study was published this month in the journal Nature. The observed phenomenon is called “kinetic magnetism” and has never been observed in solid materials. The material initially showed paramagnetism, but upon introducing more electrons into the lattice, it surprisingly became ferromagnetic.
The researchers proposed a different mechanism — as multiple electrons occupy sites in the lattice, they pair up into “doubles,” filling the entire lattice via quantum tunneling.
This causes the electrons to align their spins, resulting in ferromagnetism. The team carried out experiments to identify the type of magnetism present, applying electric current to the materials and measuring the reflection of light with different polarizations.
“This was stunning evidence of a new type of magnetism that cannot be explained by exchange interaction,” says Ataç Imamoğlu, lead author of the study.
Scientists plan to explore this phenomenon further, investigating whether it can occur at higher temperatures, as the experiments required cooling the material to a fraction above absolute zero.
The discovery promises to be a major advance in understanding magnetism and could have implications for areas such as quantum computing and data storage technology.