image: Mn3Sn exhibits large anomalous Hall effect (top left), full-electrical method to control and probe the topological spin states of Mn3Sn (top right), binary state switching (bottom left) and multistate switching (bottom right) based on magnetization switching without external magnetic field. view more
Credit: ©Science China Press
A collaboration between Kaiyou Wang's group at the Institute of Semiconductors of the Chinese Academy of Sciences and Haizhou Lu's group at Southern University of Science and Technology was recently published online in National Science Review. An external magnetic field is often required for current-induced deterministic switching of the non-collinear antiferromagnet Mn3Sn in Mn3Sn/heavy metal bilayer devices. Different from the bilayer structure, the Mn3Sn thin film directly grown on Si/SiO2 substrate has much stronger nonlinear Hall effect than that of the bilayer structure, indicating much stronger inversion symmetry broken in the device. Without external magnetic field and spin current injected from heavy metals, the current-induced magnetization deterministic switching of non-collinear antiferromagnetic Weyl semimetal can be realized by the much stronger current-induced intrinsic non-collinear spin-orbit torques in Mn3Sn itself due to stronger inversion symmetric breaking. The large anomalous Hall signal of Mn3Sn is used for detection. Based on the field-free magnetization switching of Mn3Sn, the binary state switching and multistate switching of antiferromagnetic is regulated by full electrical method. By comparing the read/write efficiency (anomalous Hall resistivity/critical switching current density) of field-free switching with ferromagnet/heavy metal heterojunction and collinear antiferromagnet/heavy metal heterojunction, it is found that, Mn3Sn has high read/write efficiency and low net magnetic moment, which proves that Mn3Sn is an efficient and stable antiferromagnetic material. This work solves the problem that antiferromagnetic materials with large signal are difficult to be regulated and detected by full electrical method, which will pave the way for the development of topological antiferromagnetic spintronics.
Journal
National Science Review