Terahertz spin currents in nanoscale spatial resolution

TL;DR

This paper introduces spintronic THz emission nanoscopy (STEN), a novel technique enabling nanoscale resolution in generating, detecting, and controlling ultrafast terahertz spin currents, overcoming diffraction limits for advanced spintronic applications.

Contribution

The study presents STEN, a new method for nanoscale coherent detection of THz spin currents that does not require invasive procedures, integrating nanophotonics, nanospintronics, and THz technology.

Findings

STEN achieves efficient injection and detection of ultrafast THz spin currents at the nanoscale.

STEN enables characterization of nanoscale spintronic heterostructures without invasion.

The platform accelerates development of high-frequency spintronic nanodevices.

Abstract

The ability to generate, detect, and control coherent terahertz (THz) spin currents with femtosecond temporal and nanoscale spatial resolution has significant ramifications. The diffraction limit of concentrated THz radiation, which has a wavelength range of 5 {\mu}m-1.5 mm, has impeded the accumulation of nanodomain data of magnetic structures and spintronic dynamics despite its potential benefits. Contemporary spintronic optoelectronic apparatuses with dimensions 100 nm presented a challenge for researchers due to this restriction. In this study, we demonstrate the use of spintronic THz emission nanoscopy (STEN), which allows for the efficient injection and precise coherent detection of ultrafast THz spin currents at the nanoscale. Furthermore, STEN is an effective method that does not require invasion for characterising and etching nanoscale spintronic heterostructures. The cohesive integration of nanophotonics, nanospintronics, and THz-nano technology into a single platform is poised to accelerate the development of high-frequency spintronic optoelectronic nanodevices and their revolutionary technical applications.