THz emission spectroscopy developed at UIUC is used to investigate spin current generation in the antiferromagnetic metal FeRh under ultrafast laser excitation. The transient spin current in FeRh can be extracted from the emitted THz field.

Developing viable platforms for the transduction between charge and spin current is crucial for spintronic based electronic devices. Our work investigates FeRh as one such platform.

We further present THz emission as a contactless probe of spin current. This probe technique can be extended to study spin dynamics in more exotic condensed matter systems such as SC/FM heterostructures, hybrid magnon systems, and quantum spin liquids which are hard to probe by conventional techniques.