Dual spin-orbit torque oscillator in magnetic recording
The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a trailing shield, and an oscillator located between the main pole and the trailing shield. The oscillator is disposed at a media facing surface (MFS). The oscillator includes a spin-torque layer sandwiched between two distinct spin Hall layers. The two distinct spin Hall layers generate spin-orbit torque (SOT) that induces in-plane precessions on opposite surfaces of the spin-torque layer, and both in-plane precessions are in the same direction. The same-direction in-plane precessions on opposite surfaces of the spin-torque layer reduce the critical current of the oscillation of the oscillator, leading to high quality recording.
1. A magnetic recording head, comprising:
a main pole; and
an oscillator disposed adjacent the main pole, wherein the oscillator comprises:
a first spin Hall layer positioned substantially perpendicular to, and a first distance from, the main pole;
a second spin Hall layer, distinct from the first spin Hall layer, and positioned substantially perpendicular to, and a second distance from, the main pole, wherein the first distance is less than the second distance; and
a spin-torque layer disposed between the first spin Hall layer and the second spin Hall layer.
2. The magnetic recording head of claim 1 , wherein the first spin Hall layer comprises platinum.
3. The magnetic recording head of claim 2 , wherein the second spin Hall layer comprises a material selected from the group consisting of beta phase tantalum and beta phase tungsten.
4. The magnetic recording head of claim 1 , wherein the first spin Hall layer has a first width, the second spin Hall layer has a second width, and the spin-torque layer has a third width, wherein the first width is substantially the same as the second width.
5. The magnetic recording head of claim 4 , wherein the third width is substantially the same as the first width or the second width.
6. The magnetic recording head of claim 4 , wherein the third width is substantially less than the first width or the second width.
7. The magnetic recording head of claim 4 , wherein the main pole includes a surface adjacent the first spin Hall layer, wherein the surface has a fourth width substantially the same as the third width.
8. The magnetic recording head of claim 1 , wherein the oscillator is disposed at a media facing surface.