THz emission driven by inverse orbital Hall effect in Te/Fe3GaTe2 heterostructures

Abstract

Terahertz (THz) spintronics is an emerging interdisciplinary field that integrates the unique advantages of spin-based electronics with the rapidly evolving frontiers of THz science. To achieve efficient THz emission at room temperature in two-dimensional (2D) spintronic devices, orbitronics could offer new conceptual approaches. In this work, we complete room-temperature THz emission in Weyl semiconductor tellurium (Te) and 2D ferromagnetic Fe3GaTe2 (FGT) heterostructures prepared by molecular beam epitaxy. The dependence of THz emission on sample orientation, pump laser polarization, and Te thickness demonstrates that the transient charge current should be dominated by the inverse orbital Hall effect (IOHE). First-principles calculations based on the density functional theory reveal that the orbital Hall conductivity of Te is approximately an order of magnitude greater than its spin Hall conductivity, thereby elucidating the underlying microscopic mechanism for the observed phenomenon. These findings not only establish a platform for further research on the Weyl semiconductor Te but also open up new opportunities for orbitronics-based THz emitters and future low-power, nanoscale spintronic applications.