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1. Prospects for Antiferromagnetic Spintronic Devices

   https://doi.org/10.1146/annurev-matsci-080222-030535  

   Khalili_Amiri, Pedram; Phatak, Charudatta; Finocchio, Giovanni (April 2024, Annual Review of Materials Research)

   This article examines recent advances in the field of antiferromagnetic spintronics from the perspective of potential device realization and applications. We discuss advances in the electrical control of antiferromagnetic order by current-induced spin–orbit torques, particularly in antiferromagnetic thin films interfaced with heavy metals. We also review possible scenarios for using voltage-controlled magnetic anisotropy as a more efficient mechanism to control antiferromagnetic order in thin films with perpendicular magnetic anisotropy. Next, we discuss the problem of electrical detection (i.e., readout) of antiferromagnetic order and highlight recent experimental advances in realizing anomalous Hall and tunneling magnetoresistance effects in thin films and tunnel junctions, respectively, which are based on noncollinear antiferromagnets. Understanding the domain structure and dynamics of antiferromagnetic materials is essential for engineering their properties for applications. For this reason, we then provide an overview of imaging techniques as well as micromagnetic simulation approaches for antiferromagnets. Finally, we present a perspective on potential applications of antiferromagnets for magnetic memory devices, terahertz sources, and detectors. 

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2. Observation of Real‐Time Spin‐Orbit Torque Driven Dynamics in Antiferromagnetic Thin Film

   https://doi.org/10.1002/adma.202417240  

   Cheng, Yang; Huang, Hanshen; Tang, Junyu; Lanier, Joseph; Lazareno, Katelyn; Chang, Hao‐Kai; Chui, Shang‐Jui; Yang, Chao‐Yao; Yang, Fengyuan; Cheng, Ran; et al (March 2025, Advanced Materials)

   Abstract In the burgeoning field of spintronics, antiferromagnetic materials (AFMs) are attracting significant attention for their potential to enable ultra‐fast, energy‐efficient devices. Thin films of AFMs are particularly promising for practical applications due to their compatibility with spin‐orbit torque (SOT) mechanisms. However, studying these thin films presents challenges, primarily due to the weak signals they produce and the rapid dynamics driven by SOT, that are too fast for conventional electric transport or microwave techniques to capture. The time‐resolved magneto‐optical Kerr effect (TR‐MOKE) has been a successful tool for probing antiferromagnetic dynamics in bulk materials, thanks to its sub‐picosecond (sub‐ps) time resolution. Yet, its application to nanometer‐scale thin films has been limited by the difficulty of detecting weak signals in such small volumes. In this study, the first successful observation of antiferromagnetic dynamics are presented in nanometer‐thick orthoferrite films using the pump‐probe technique to detect TR‐MOKE signal. This paper report an exceptionally low damping constant of 1.5 × 10⁻⁴and confirms the AFM magnonic nature of these dynamics through angular‐dependent measurements. Furthermore, it is observed that electrical currents can potentially modulate these dynamics via SOT. The findings lay the groundwork for developing tunable, energy‐efficient spintronic devices, paving the way for advancements in next‐generation spintronic applications. 

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3. Spin Waves and Magnetic Exchange Hamiltonian in CrSBr

   https://doi.org/10.1002/advs.202202467  

   Scheie, Allen; Ziebel, Michael; Chica, Daniel G; Bae, Youn June; Wang, Xiaoping; Kolesnikov, Alexander I; Zhu, Xiaoyang; Roy, Xavier (September 2022, Advanced Science)

   Abstract CrSBr is an air‐stable two‐dimensional (2D) van der Waals semiconducting magnet with great technological promise, but its atomic‐scale magnetic interactions—crucial information for high‐frequency switching—are poorly understood. An experimental study is presented to determine the CrSBr magnetic exchange Hamiltonian and bulk magnon spectrum. TheA‐type antiferromagnetic order using single crystal neutron diffraction is confirmed here. The magnon dispersions are also measured using inelastic neutron scattering and rigorously fit the excitation modes to a spin wave model. The magnon spectrum is well described by an intra‐plane ferromagnetic Heisenberg exchange model with seven nearest in‐plane exchanges. This fitted exchange Hamiltonian enables theoretical predictions of CrSBr behavior: as one example, the fitted Hamiltonian is used to predict the presence of chiral magnon edge modes with a spin‐orbit enhanced CrSBr heterostructure. 

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4. Exchange Bias Between van der Waals Materials: Tilted Magnetic States and Field‐Free Spin–Orbit‐Torque Switching

   https://doi.org/10.1002/adma.202305739  

   Cham, Thow_Min Jerald; Dorrian, Reiley J; Zhang, Xiyue S; Dismukes, Avalon H; Chica, Daniel G; May, Andrew F; Roy, Xavier; Muller, David A; Ralph, Daniel C; Luo, Yunqiu Kelly (March 2024, Advanced Materials)

   Abstract Magnetic van der Waals heterostructures provide a unique platform to study magnetism and spintronics device concepts in the 2D limit. Here, studies of exchange bias from the van der Waals antiferromagnet CrSBr acting on the van der Waals ferromagnet Fe₃GeTe₂(FGT) are reported. The orientation of the exchange bias is along the in‐plane easy axis of CrSBr, perpendicular to the out‐of‐plane anisotropy of the FGT, inducing a strongly tilted magnetic configuration in the FGT. Furthermore, the in‐plane exchange bias provides sufficient symmetry breaking to allow deterministic spin–orbit torque switching of the FGT in CrSBr/FGT/Pt samples at zero applied magnetic field. A minimum thickness of the CrSBr of >10 nm is needed to provide a non‐zero exchange bias at 30 K. 

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5. Giant Spin-flop magnetoresistance in a collinear antiferromagnetic tunnel junction

   https://doi.org/10.1038/s41467-025-62695-w  

   Xu, Shijie; Zhang, Zhizhong; Mahfouzi, Farzad; Huang, Yan; Cheng, Houyi; Dai, Bingqian; Kim, Jinwoong; Zhu, Daoqian; Cai, Wenlong; Shi, Kewen; et al (December 2025, Nature Communications)

   Collinear antiferromagnetic (AFM) materials have the unique promise of no stray fields, displaying ultrafast dynamics, and being robust against perturbation fields which motivate the extensive research of antiferromagnetic spintronics. However, the detection of antiferromagnetic order poses formidable challenges. Here, we report the electrical detection of colinear antiferromagnetism in all-epitaxial RuO2/MgO/RuO2 tunnel junctions (TJ) using spin-flop tunneling anisotropic magnetoresistance (TAMR). We measured a TAMR ratio of around 60% at room temperature, which arises from the switching between the parallel and perpendicular configurations of the adjacent collinear AFM state. Furthermore, we carried out angular-dependent measurements using this antiferromagnetic tunnel junction (AFM-TJ) and showed that the magnitude of anisotropic longitudinal magnetoresistance in the AFM-TJ can be controlled by the direction of an external magnetic field. First principles electronic structure calculations corroborate that the collinear antiferromagnetic TJ may produce a substantially large TAMR ratio. The emergence of resonant interfacial states, combined with the tunneling transmission through the MgO barrier and the substantial spin-orbit coupling (SOC) strength of Ru, especially when augmented by oxygen doping, leads to the significant enhancement observed in the tunneling anisotropic magnetoresistance (TAMR). Our work not only propels antiferromagnetic materials to the forefront of spintronic device innovation but also unveils a novel paradigm for electrically controlled antiferromagnetic spintronics, auguring transformative advancements in high-speed, low-energy information devices. 

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