Researchers develop mechanism of electrical 180° switching of Néel vector in spin-splitting antiferromagnet

A research team led by The Hong Kong University of Science and Technology (HKUST) and Tsinghua University has theoretically proposed a new mechanism of electrical 180° switching of Néel vector and experimentally realized ...

The study is published in Science Advances . Antiferromagnetic spintronics has sparked widespread interest due to its enormous potential for creating ultra-dense and ultrafast antiferromagnetic memory that is suitable for modern high-performance information technologies. The electrical 180° switching of the Néel vector is a long-term objective for producing electrically controllable antiferromagnetic memory using opposite Néel vectors as binary "0" and "1." However, the state-of-art antiferromagnetic switching mechanisms have long been limited to 90° or 120° switching of Néel vector, which unavoidably requires multiple writing channels that contradict ultradense integration.

The study of electrical 180° switching of Néel vector makes spin-splitting antiferromagnet a new potential candidate for ultrafast memory. Specifically, in collinear antiferromagnet, the Néel vector n has two stable states: n + and n - with symmetric energy barriers. To leave an asymmetry of energy barriers, the team led by Prof. Liu Junwei, Associate Professor at the Department of Physics at HKUST proposed to exert an external magnetic field to interact with the tiny DMI-induced moment.

Figure 1 (a) Sketch map of the symmetric (black line) and asymmetric (red line) energy barriers for switching Néel vector n . Credit: HKUST Read more

Figure 1 (b) Atomic spin simulation of Néel vector n in antiferromagnet Mn 5 Si 3 . Credit: HKUST Read more

Figure 1 (c) Anomalous Hall conductivities of different antiferromagnetic configurations calculated by tight-binding method. Credit: HKUST Read more

Figure 1 (d) Good cyclic performance of the antiferromagnetic Mn 5 Si 3 device. Credit: HKUST Read more

Figure 2. Spin-splitting energy bands of (a) T-paired SVL and (b) C-paired SVL. Credit: HKUST Read more