Nanoscale Imaging and Control of Altermagnetism in MnTe

Altermagnetism is effectively a hybrid form of magnetism and ferromagnetism that might become very useful in magnetic storage as well as spintronics in general. In order to practically use it, we first need to be able to control the creation of these altermagnets, which is what researchers have now taken the first steps towards. The research paper by [O. J. Amin] et al. was published earlier this month in Nature. It builds upon the team’s earlier research, including the detection of altermagnetism in manganese telluride (MnTe). This new study uses the same material but uses a photoemission electron microscope (PEEM) with X-rays to image these nanoscale altermagnetic structures.

Additionally, the spin orientation of these altermagnetic structures within the MnTe was controlled using microstructure patterning and thermal cycling in magnetic fields. The micropatterning with electron beam lithography enabled the creation of large single-domain altermagnetic structures, which is promising for further research. As noted in the outlook section by the researchers, this part of the research is still very much about creating the basic means to use altermagnetism, even for something as seemingly straightforward as data storage. In this particular study, the reading (imaging) mechanism was an expensive PEEM setup with the X-rays produced by a synchrotron.

Honestly, we still struggle to figure out plain old magnetism. Obviously, there’s more to it than that.

Heading image: Illustrative models of collinear ferromagnetism, antiferromagnetism, and altermagnetism in crystal-structure real space and nonrelativistic electronic-structure momentum space. (Credit: Libor Šmejkal et al., Phys. Rev. X, 2022)