Advances in altermagnet-based devices.

Altermagnetism has emerged as a third fundamental magnetic phase, uniquely combining the zero net magnetization and ultrafast dynamics of antiferromagnets with spin splitting typically reserved for ferromagnets(FMs). This review provides a systematic overview of the burgeoning field of altermagnets(AMs) and AM-based devices. We first present the symmetry principles that enable non-relativistic spin splitting. Then we examine representative material candidates-ranging from bulk systems to emergent van der Waals layers and metal-organic frameworks, and evaluate their applications in functional devices. Special focus is given to tunneling junctions, anomalous Hall effect sensors, and terahertz (THz) devices. Finally, we discuss methods for electrical and mechanical control of altermagnetic states and the effects between altermagnetism and superconductivity, offering a perspective on the challenges and opportunities for this new paradigm of energy-efficient spintronics.