Current-induced magnetic switching with spin-orbit torque in an interlayer-coupled junction with a Ta spacer layer

Abstract

Spin-orbit torque has attracted considerable attention as a means to overcome limits of devices based on spin-transfer torque. However, a small magnetic field that is collinear to the current flow must be applied to break symmetry and induce deterministic current-induced magnetization switching. Recently, a junction utilizing interlayer coupling mediated by a Ru spacer layer between two CoFe layers was designed for symmetry breaking and exhibited current-induced magnetization switching without a magnetic field. Here, we demonstrate zero-field current-induced switching of the perpendicular magnetization of a Co layer that is indirectly coupled with a CoFe layer via a Ta spacer. The weak interlayer coupling exhibited by Ta allows the layer thickness to be relatively small (≈0.5 nm), enabling appropriate interlayer coupling to induce spin-orbit torque for current-induced magnetic switching. External magnetic field effects on switching characteristics show that the current switching process is quite stable against external environments.

Detecting quadrupole: a hidden source of magnetic anisotropy for Manganese alloys

“…Therefore, orbital moment anisotropy cannot explain the PMA of the order of 10 6 J/m 3 in Mn 3− δ Ga 26 . As the electron configuration is close to the half-filled 3d 5 case, the quenching of the orbital angular momentum occurs in principle. In Mn 3− δ Ga, since the electron filling is not complete half-filled cases, small orbital angular momentum appears.…”

Current‐Induced Spin–Orbit Torques for Spintronic Applications

“…Various approaches have been suggested to achieve field-free SOT switching of perpendicular magnetization; one utilizes an internal effective magnetic field generated within the SOT device such as an exchange-biased field from antiferromagnet (AFM), [105][106][107] or an interlayer or stray fields from a remote FM layer in the device. [108][109][110] Another approach is to generate spin current with an out-of-plane component of spin polarization using FM/NM/FM trilayers [111][112][113][114] or competing spin currents in NM/FM multilayers, [115] or material systems with lateral inversion asymmetry. [61,[116][117][118][119] In this Progress Report, we present recent progress in SOT research and discuss the advantages and challenges of SOT-based spintronic devices.…”

“…One approach is to introduce an internal effective magnetic field induced within the SOT structure, for instance an exchange-biased field generated from an AFM [105][106][107] and an interlayer coupling field produced by a FM through a nonmagnetic spacer. [108][109][110]149] The other approach is to generate spin current and an associated SOT that includes an out-of-plane (z-) component, which has been demonstrated in laterally asymmetric structures, [61,[116][117][118][119] or in magnetic trilayers where the interface-generated spin current has a z-component of spin polarization. [111][112][113][114][115]…”

Chiral-induced switching of antiferromagnet spins in a confined nanowire

“…Because SOT devices use a current, charge scattering and corresponding Joule heating inevitably occur [21]. This intrinsic property is an obstacle in reducing the switching power, although SOT efficiency is significantly improved in nanoscale devices [7,10,[22][23][24][25][26]. In heterostructures, especially with structural inversion asymmetry, Dzyaloshinskii-Moriya (DM) interaction, which is also induced by spin-orbit coupling, has received attention in spin dynamics research.…”