Field-free perpendicular magnetization switching of low critical current density at room temperature in TaIrTe4/ferromagnet heterostructures

Abstract

Spin–orbit torque-induced perpendicular magnetization switching has attracted much attention due to the advantages of nonvolatility, high density, infinite read/write counts, and low power consumption in spintronic applications. To achieve field-free deterministic switching of perpendicular magnetization, additional magnetic field, magnetic layer assistance, or artificially designed structural symmetry breaking are usually required, which are not conducive to the high-density integration and application of low-power devices. However, 2D type-II Weyl semimetals with low-symmetry structures have recently been found to generate z-spin-polarized currents, which may induce out-of-plane damping-like torques to their neighboring ferromagnetic layers, and realize deterministic perpendicular magnetization switching at zero magnetic field. In this Letter, we report that current-induced field-free magnetization switching at room temperature can be achieved in a perpendicularly magnetized TaIrTe4/Pt/Co/Pt device, and the critical switching current density can be lowered to be about 2.64 × 105 A·cm−2. When the current is applied along the low-symmetry TaIrTe4a-axis, the out-of-plane and in-plane spin Hall conductivities are estimated to be 0.61 × 105 × ℏ/2e (Ω m)−1 and 3.13 × 105 × ℏ/2e (Ω m)−1, respectively. This study suggests that TaIrTe4 has great potential for the design of room-temperature efficient spintronic devices.