Magnetism
in two dimensions is one of the most intriguing and alluring
phenomena in condensed matter physics. Atomically thin 2D materials
have emerged as a promising platform for exploring magnetic properties,
leading to the development of essential technologies such as supercomputing
and data storage. Arising from spin and charge dynamics in elementary
particles, magnetism has also unraveled promising advances in spintronic
devices and spin-dependent optoelectronics and photonics. Recently,
antiferromagnetism in 2D materials has received extensive attention,
leading to significant advances in their understanding and emerging
applications; such materials have zero net magnetic moment yet are
internally magnetic. Several theoretical and experimental approaches
have been proposed to probe, characterize, and modulate the magnetic
states efficiently in such systems. This Review presents the latest
developments and current status for tuning the magnetic properties
in distinct 2D van der Waals antiferromagnets. Various state-of-the-art
optical techniques deployed to investigate magnetic textures and dynamics
are discussed. Furthermore, device concepts based on antiferromagnetic
spintronics are scrutinized. We conclude with remarks on related challenges
and technological outlook in this rapidly expanding field.