  The manipulation of magnetic properties using either electrical currents or
gate bias is the key of future high-impact nanospintronics applications such as
spin-valve read heads, non-volatile logic, and random-access memories. The
current technology for magnetic switching with spin-transfer torque requires
high current densities, whereas gate-tunable magnetic materials such as
ferromagnetic semiconductors and multiferroic materials are still far from
practical applications. Recently, magnetic switching induced by pure spin
currents using the spin Hall and Rashba effects in heavy metals, called
spin-orbit torque (SOT), has emerged as a candidate for designing
next-generation magnetic memory with low current densities. The recent
discovery of topological materials and two-dimensional (2D) van der Waals (vdW)
materials provides opportunities to explore versatile 3D-2D and 2D-2D
heterostructures with interesting characteristics. In this review, we introduce
the emerging approaches to realizing SOT nanodevices including techniques to
evaluate the SOT efficiency as well as the opportunities and challenges of
using 2D topological materials and vdW materials in such applications.
