Terahertz Signal Detectors Based on Antiferromagnetic Spintronic Nanostructures

Antiferromagnetic spintronic detectors are nanoscale multilayer devices consisting of a layer of antiferromagnet and capable of generating a low frequency or DC output voltage under the action of a (sub-) terahertz frequency input signal. In a general case, an input AC signal current applied to the detector excites the current-driven (sub-) terahertz frequency dynamics of magnetic sublattices in its antiferromagnetic layer, which then leads to the generation of the detector output voltage across the whole structure due to several possible effects depending on the device materials and geometry. Like the conventional ferromagnet-based spintronic detectors, which are now considered as promising signal detectors for microwave applications, the detectors based on antiferromagnetic nanostructures can be promising for many terahertz applications, including terahertz signal detection, spectrum analysis, and energy harvesting. In this chapter, we review the principles of operation of antiferromagnetic spintronic detectors, discuss their key features compared to the conventional ferromagnet-based detectors, and also review the recent advances, trends, and problems in the physics and applications of antiferromagnetic spintronic detectors.