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Friction plays an essential role in most physical processes that we experience in our everyday life. Examples range from our ability to walk or swim, to setting boundaries of speed and fuel efficiency of moving vehicles. In magnetic systems, the displacement of chiral domain walls (DW) and skyrmions (SK) by Spin Orbit Torques (SOT), is also prone to friction. Chiral damping (αc), the dissipative counterpart of the Dzyaloshinskii Moriya Interaction (DMI), plays a central role in these dynamics. Despite experimental observation, and numerous theoretical studies confirming its existence, the influence of chiral damping on DW and SK dynamics has remained elusive due to the difficulty of discriminating from DMI. Here we unveil the effect that αc has on the flow motion of DWs and SKs driven by current and magnetic field. We use a static in-plane field to lift the chiral degeneracy. As the in-plane field is increased, the chiral asymmetry changes sign. When considered separately, neither DMI nor αc can explain the sign reversal of the asymmetry, which we prove to be the result of their competing effects. Finally, numerical modelling unveils the non-linear nature of chiral dissipation and its critical role for the stabilization of moving SKs. Chiral damping plays a critical role in the motion of skyrmions and domain walls, but it difficult to distinguish its influence from Dzyaloshinskii Moriya Interaction (DMI). Here, Safeer et al show that competition between chiral damping and the DMI result in a sign change in the chiral asymmetry. [ABSTRACT FROM AUTHOR]

We report on the current-induced magnetization switching of a three-terminal perpendicular magnetic tunnel junction by spin-orbit torque and its read-out using the tunnelling magnetoresistance (TMR) effect. The device is composed of a perpendicular Ta/FeCoB/MgO/FeCoB stack on top of a Ta current line. The magnetization of the bottom FeCoB layer can be switched reproducibly by the injection of current pulses with density 5×1011 A/m2 in the Ta layer in the presence of an in-plane bias magnetic field, leading to the full-scale change of the TMR signal. Our work demonstrates the proof of concept of a perpendicular spin-orbit torque magnetic memory cell. [ABSTRACT FROM AUTHOR]

The article discusses a study by Guoqiang Yu and co-workers which demonstrates that spin orbit torques can switch the magnetization in perpendicularly magnetized thin films without an external magnetic field. Topics discussed include spin orbit interaction, centrosymmetric property of ferromagnetic metals and macroscopic switching of the magnetization. The microscopic mechanism shown in the study is useful for magnetic random access memories.