National University of Singapore

Jongmin Lee

Hyunsoo Yang

Rajagopalan Ramaswamy

In example embodiments, a SOT magnetic memory and operation method are provided that utilize SOT driven domain wall motion to achieve subsequent switching without the need for an external assist magnetic field. The magnetic memory includes a magnetic tunnel junction having a reference layer, a tunnel barrier layer and a free layer, where the tunnel barrier layer is positioned between the reference layer and free layer. A spin-orbit torque layer is disposed adjacent to the free layer. A pair of pinning site are positioned at a longitudinal end of the free layer and each has an opposite magnetization direction from the other. The SOT layer is configured to exert SOT and switch a magnetization direction of the free layer via domain wall motion in a direction of current flow when an electric current is passed through a length of the SOT layer.

Magnetic memory and a method of operating magnetic memory

In various embodiments, techniques are provided for unipolar SOT switching of a magnetic memory, using current pulses with differing pulse durations or current densities. For example, to switch a MTJ to a high resistance state, in-plane current pulses having a first pulse duration may be applied. To switch the MTJ to a low resistance state, in-plane current pulses having a second pulse duration may be applied. The pulse's polarity and current density may be fixed, and the polarity and magnitude of an in-plane assist field may be fixed. Alternatively, to switch a MTJ to a high resistance state in-plane current pulses having a first current density may be applied. To switch the MTJ to a low resistance state in-plane current pulses having a second current density may be applied. The pulse's polarity and duration may be fixed, and the polarity and magnitude of an in-plane assist field may be fixed.

Growing community of inventors

Singapore, Singapore

Jongmin Lee