| Abstract Scope |
Altermagnetism is a novel “ferroic” magnetism proposed by Šmejkal et al, which achieves spin splitting, even in an antiferromagnet due to its specific crystal structure. This results in the generation of a spin current with spin polarization dependent on the Neìel vector interestingly. This phenomenon is referred to as the spin-splitter effect (SSE), leading to the generation of novel spin current, compared with spin Hall effect (SHE).
We have observed the unconventional generation of spin current in an altermagnetic RuO2(101) with spins of all -, - and -polarizations depending on crystal orientation (applied current direction). This observation was made using spin-torque ferromagnetic resonance technique in an adjacent NiFe alloy layer at room temperature. From the perspective of Neìel vector-dependent polarization, this feature is in good agreement with the proposed theory of SSE.
Furthermore, we have achieved field-free magnetization switching in a neighboring Co layer with perpendicular magnetization using a -polarized spin current driven by SSE in RuO2. Thus, we have experimentally observed the SSE and demonstrated its utility for spintronic applications.
In this meeting, I would like to provide more detailed information on the properties of altermagnetism and the actual experiments related to exotic spin current generation with comparison to conventional SHE in spintronics. |