Layered Co1/4TaSe2 shows evidence of altermagnetic spin splitting

Researchers writing in Nature Communications report evidence of altermagnetism in Co1/4TaSe2, a crystal with cobalt atoms between tantalum diselenide layers. At 7 K, spin-sensitive measurements found electron spin polarization changing with momentum, consistent with their calculations. The spin splitting vanished at 200 K, above the material’s 178 K magnetic transition. The researchers suggest its layered structure could be useful for future studies of interfaces and heterostructures.