Antiferromagnetism: An efficient and controllable spin source

Abstract

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.

Field‐Free Spin‐Orbit Torque Driven Perpendicular Magnetization Switching of Ferrimagnetic Layer Based on Noncollinear Antiferromagnetic Spin Source

“…In Mn 3 Sn, the Mn atoms form a triangular sublattice in the c-plane (0001) known as the Kagome lattice, and their net magnetic moments are disclosed from a noncollinear 120°ordered chiral spin texture. [20,21] This unique spin texture leads to novel physical properties, including magnetic spin Hall effect (MSHE), [22][23][24] controllable spin polarization direction in spin current, [25,26] enhanced charge-spin conversion efficiency, [27,28] and the damping-like torque along the out-of-plane direction that can efficiently drive perpendicular magnetization switching. [29,30] Recent studies have investigated noncollinear antiferromagnetic Mn 3 Sn as either a magnetization switching layer [31][32][33][34][35][36] or a spin source layer [29,30,37] in various heterostructures.…”

Engineering buffer layers to improve temperature resilience of magnetic tunnel junction sensors

“…Notwithstanding, the ability to customize the magnetic properties of AFM/FM bilayers is of the utmost interest in applications beyond magnetoresistive sensors. Such a versatile and seamless manner as stack engineering, even combining different growth methods as demonstrated here, provides advantages to push further applications in perpendicular magnetized architectures [45], and improving electrical control and readout [31,32] in AFM spintronics [46].…”

Simultaneous High Charge‐Spin Conversion Efficiency and Large Spin Diffusion Length in Altermagnetic RuO2

“…[47,48] Moreover, ASSE is a bulk effect leading to thickness-dependent values for RuO 2 . Therefore, the comparison in this paper is conducted based on the following two standards: i) The data acquired by ST-FMR, SP, and harmonic Hall measurements methods, which are three representative approaches to quantify 𝜃 SH and 𝜆 SD with vertical test configuration, [49,50] are taken into consideration for the comparison; ii) the 𝜃 SH and 𝜆 SD values of RuO 2 are selected from the ST-FMR results with more adequate testing samples. As a reference line of |𝜃 SH 𝜆 SD | = 1 nm, the curve in Figure 6 (dashdotted curve) indicates the inverse relationship of 𝜃 SH and 𝜆 SD .…”