Antiferromagnets represent a new opportunity for developing spintronics with superior speed and high device density. With zero net magnetic moment, they are immune to almost any external magnetic field disturbance. Meanwhile, the intrinsic dynamics at the Terahertz frequency makes them good candidates for high speed electronics. While a lot of useful ways have been developed for manipulating spins in ferromagnets over the past decades, people’s knowledge on detecting and controlling antiferromagnetic ordering remains very limited. As a matter of fact, spurious effects have been mistakenly taken as signs of antiferromagnetic switching in quite a few literatures, as our paper pointed out [1].
Recently, by developing antiferromagnetic thin films with a canted crystal orientation, we realized a configuration where the spins from applied electrical currents can be efficiently injected into antiferromagnet and realize real switching of antiferromagnets [2]. This electrical control over antiferromagnetic ordering happens both on collinear antiferromagnets with dual sublattices, and on topological antiferromagnets with three sublattices arranged in a non-collinear geometry [3]. These studies introduce new platforms for quantitatively understanding switching and oscillation dynamics in antiferromagnets.
References:
[1] P. Zhang, J. Finley, T. Safi, et al., L. Liu, Phys. Rev. Lett. 123, 247206 (2019).
[2] P. Zhang, C.-T. Chou, H. Yun, et al.,L. Liu, Phys. Rev. Lett. 129, 017203 (2022).
[3] J.-Y. Yoon et al., L. Liu, Nat. Mater (2023) doi: 10.1038/s41563-023-01620-2
Luqiao Liu is an Associate Professor of Electrical Engineering at Massachusetts Institute of Technology. He received his B.S. in physics from Peking University in 2006, and Ph.D. in Applied Physics from Cornell University in 2012. He worked as a Research Staff Member at IBM Watson Research Center before joining MIT in 2015. Luqiao’s current research focuses on spintronic material and devices for memory and logic applications. Luqiao Liu has received McMillan Award, NSF Career Award, Air Force Young Investigator Award, Sloan Fellowship, and International Union of Pure and Applied Physics Young Scientist Award.