Scientists Found a World of Magnetism Never Seen Before in MnTe

A third magnetic class

For decades, magnetic materials were commonly grouped as ferromagnets or antiferromagnets. In ferromagnets, electronic spins point in the same direction and create a net magnetic field; in antiferromagnets, alternating spins cancel one another.

Altermagnets combine aspects of both groups. Their spins alternate and cancel, like those in antiferromagnets, but they can also carry spin currents, a property associated with ferromagnets.

Evidence from manganese telluride

Manganese telluride, or MnTe, is one material that exhibits altermagnetic properties. Scientists named the phenomenon in 2022, and further evidence emerged two years later.

X-rays reveal a signature

The researchers examined how materials scatter left- and right-handed polarized X-ray beams. Chiral materials scatter the two beams differently, while non-chiral materials scatter them in the same way.

Daniel Jost, a SLAC associate scientist and the study’s lead author, said the chiral signature provided firm experimental grounds for treating altermagnetism as its own class. He said the results offer robust confirmation that the third phase is real.

Potential for future devices

The findings address a missing piece of experimental proof for altermagnetism, which researchers have increasingly discussed in recent years. The reported combination of properties may make the materials relevant to tomorrow’s quantum devices.

Jost said researchers had gathered evidence of a third type of magnetism bridging the qualities of ferromagnets and antiferromagnets. The new results support that interpretation.