Current-induced spin-orbit field in permalloy interfaced with ultrathin Ti and Cu

Abstract

How spin-orbit torques emerge from materials with weak spin-orbit coupling (e.g., light metals) is an open question in spintronics. Here, we report on a field-like spin-orbit torque (i.e., in-plane spin-orbit field transverse to the current axis) in SiO${}_2$-sandwiched permalloy (Py), with the top Py-SiO${}_2$ interface incorporating ultrathin Ti or Cu. In both SiO${}_2$/Py/Ti/SiO${}_2$ and SiO${}_2$/Py/Cu/SiO${}_2$, this spin-orbit field opposes the classical Oersted field. While the magnitude of the spin-orbit field is at least a factor of 3 greater than the Oersted field, we do not observe evidence for a significant damping-like torque in SiO${}_2$/Py/Ti/SiO${}_2$ or SiO${}_2$/Py/Cu/SiO${}_2$. Our findings point to contributions from a Rashba-Edelstein effect or spin-orbit precession at the (Ti, Cu)-inserted interface.

References in corpus (3)

• Quasiclassical approach to the spin-Hall effect in the two-dimensional electron gas
• Spontaneous Edge Accumulation of Spin Currents in Finite-Size Two-Dimensional Diffusive Spin-Orbit Coupled SFS Heterostructures
• Long-Range Spin-Triplet Correlations and Edge Spin Currents in Diffusive Spin-Orbit Coupled SNS Hybrids with a Single Spin-Active Interface