Facilitating field-free perpendicular magnetization switching with a Berry curvature dipole in a Weyl semimetal

We report the synergy between orbital and spin-orbit torques in ${\mathrm{WTe}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{GeTe}}_{2}$ heterostructures characterized by a Berry curvature dipole. By applying a current along the $a$ axis in ${\mathrm{WTe}}_{2}$, we detect an out-of-plane magnetization in the system, which we attribute to nonequilibrium orbital magnetization linked to the Berry curvature dipole based on first-principles calculations, manifesting as the orbital Edelstein effect. This effect generates orbital torques that enable field-free perpendicular magnetization switching. Furthermore, by applying a relatively small current along the $a$ axis and a pulsed current along the $b$ axis in ${\mathrm{WTe}}_{2}$, we demonstrate controllable field-free magnetization switching of the adjacent ${\mathrm{Fe}}_{3}{\mathrm{GeTe}}_{2}$ layer, independently manipulating the orbital and spin-orbit torques. Our findings not only enhance the understanding of the collaborative dynamics between these torques but also suggest potential applications in magnetoresistive random-access memory.