Physicists Find New Type of Magnetism

Physicists have discovered a new type of magnetism, called altermagnetism, in a material known as cobalt-intercalated tantalum diselenide (Co 1/4 TaSe 2 ). This type of magnetism combines features of ferromagnetism and antiferromagnetism, and could lead to the development of faster, more efficient computers.

In ferromagnets, atomic spins line up in the same direction, while in antiferromagnets, neighboring spins point in opposite directions and cancel each other out. Altermagnets, on the other hand, have no net magnetization, but their electrons behave as if the material were magnetic.

The researchers used a technique called angle-resolved photoemission spectroscopy to study the material's electronic structure. They found a characteristic splitting in the electronic bands of Co 1/4 TaSe 2, and further analysis revealed that the split states carried opposite spin polarizations, which is a key evidence of altermagnetism.

Altermagnets could be useful for spintronics, which aims to build faster, more efficient electronics that use electron spin rather than just charge. Because altermagnets produce no stray magnetic fields, devices made from them could be packed closely without interfering with each other.

Madhab Neupane, a professor of physics at the University of Central Florida, led the research team. He said that altermagnets offer another possibility by combining desirable characteristics of both ferromagnets and antiferromagnets.

The discovery of altermagnetism could lead to the development of new electronic devices that use spin currents to transmit information. Researchers are investigating whether these spin currents could eventually carry information through future electronic systems.

The material Co 1/4 TaSe 2 is a layered material that contains magnetic cobalt atoms. It could serve as a flexible experimental platform for studying altermagnetism and potentially advancing electronic and spintronic technologies.