Efficient Spin-Orbit Torque Switching of the Semiconducting Van Der Waals Ferromagnet Cr₂ Ge₂ Te₆.

Abstract

Being able to electrically manipulate the magnetic properties in recently discovered van der Waals ferromagnets is essential for their integration in future spintronics devices. Here, the magnetization of a semiconducting 2D ferromagnet, i.e., Cr₂ Ge₂ Te₆ , is studied using the anomalous Hall effect in Cr₂ Ge₂ Te₆ /tantalum heterostructures. The thinner the flakes, hysteresis and remanence in the magnetization loop with out-of-plane magnetic fields become more prominent. In order to manipulate the magnetization in such thin flakes, a combination of an in-plane magnetic field and a charge current flowing through Ta-a heavy metal exhibiting giant spin Hall effect-is used. In the presence of in-plane fields of 20 mT, charge current densities as low as 5 × 10⁵ A cm^-2 are sufficient to switch the out-of-plane magnetization of Cr₂ Ge₂ Te₆ . This finding highlights that current densities required for spin-orbit torque switching of Cr₂ Ge₂ Te₆ are about two orders of magnitude lower than those required for switching nonlayered metallic ferromagnets such as CoFeB. The results presented here show the potential of 2D ferromagnets for low-power memory and logic applications.