Antiferromagnetism: An efficient and controllable spin source

Antiferromagnetic (AFM) spintronics is an emerging field, with significant advances in particular in the study of the tunable spin generation, transport, manipulation, and detection based on the control and probe of AFM moments. The Néel-vector-dependent spin current generation in AFM materials makes them an efficient and controllable spin source, paving the way for future spintronic devices with ultralow power consumption and high operability. Herein, we aim to provide a comprehensive review of recent progress in charge-spin conversion mediated by AFMs. First, we present a brief summary of several typical characterization techniques of charge-spin conversion. Then, we focus on the recent efforts for improving the charge-spin conversion efficiency and performances of spin torques in the antiferromagnet/ferromagnet bilayer. In the third part, we review the controllable spin current and multidirectional spin polarization generated by AFMs and the resultant field-free magnetization switching. Finally, we discuss the prospects of the AFM spin sources, which will inspire more in-depth studies and advance practical applications.