Altermagnetism in the layered intercalated transition metal dichalcogenide CoNb4Se8
Resham Babu Regmi, Hari Bhandari, Bishal Thapa, Yiqing Hao, Nileema Sharma, J. Douglas McKenzie, Xinglong Chen, Abhijeet Nayak, Mohamed El Gazzah, Bence G. Márkus, Lászlø Forró, Xiaolong Liu, Huibo Cao, J. F. Mitchell, I. I. Mazin, N. Ghimire
Abstract
Altermagnets (AMs) are a new class of magnetic materials that combine the beneficial spintronics properties of ferromagnets and antiferromagnets, garnering significant attention recently. Here, we have identified altermagnetism in a layered intercalated transition metal diselenide, CoNb4Se8, which crystallizes with an ordered sublattice of intercalated Co atoms between NbSe2 layers. Single crystals are synthesized, and the structural characterizations are performed using single crystal diffraction and scanning tunneling microscopy. Magnetic measurements reveal easy-axis antiferromagnetism below 168 K. Density functional theory (DFT) calculations indicate that A-type antiferromagnetic ordering with easy-axis spin direction is the ground state, which is verified through single crystal neutron diffraction experiments. Electronic band structure calculations in this magnetic state display spin-split bands, confirming altermagnetism in this compound. The layered structure of CoNb4Se8 presents a promising platform for testing various predicted properties associated with altermagnetism. Altermagnets combine the spin splitting of ferromagnets and the magnetic ordering of collinear antiferromagnets. These technologically promising features have led to an aggressive search for altermagnetic materials. Here, Regmi et al synthesize CoNb4Se8, a layered intercalated material, and confirm altermagnetism via a combination of neutron and magnetotransport measurements and DFT calculations.