Higher areal density non-local spin orbit torque (SOT) writer with topological insulator materials
The present disclosure generally relates to a magnetic media drive comprising a magnetic recording head. The magnetic recording head comprises a main pole disposed at a media facing surface (MFS), a shield disposed at the MFS, a spin blocking layer disposed between the shield and the main pole, at least one non-magnetic layer disposed between the main pole and the shield, the at least one non-magnetic layer being disposed at the MFS, and at least one spin orbit torque (SOT) layer disposed over the at least one non-magnetic layer, the SOT layer being recessed a distance of about 20 nm to about 100 nm from the MFS. A ratio of a length of the SOT layer to a thickness of the SOT layer is greater than 1. The at least one SOT layer comprises BiSb.
1. A magnetic recording head, comprising:
a main pole disposed at a media facing surface (MFS);
a shield disposed at the MFS;
a non-magnetic layer disposed between the main pole and the shield, the non-magnetic layer being disposed at the MFS, wherein the non-magnetic layer is tapered in shape; and
a spin orbit torque (SOT) layer disposed over the non-magnetic layer, the SOT layer being recessed a distance of about 20 nm to about 100 nm from the MFS.
2. The magnetic recording head of claim 1 , wherein a ratio of a length of the SOT layer to a thickness of the SOT layer is greater than 1.
3. The magnetic recording head of claim 1 , wherein a length of the non-magnetic layer is substantially equal to a length of the SOT layer.
4. The magnetic recording head of claim 1 , wherein the SOT layer comprises undoped BiSb.
5. The magnetic recording head of claim 1 , wherein the SOT layer comprises doped BiSbX, where the dopant is less than about 10 at. %, and where X is a material selected from the group consisting of: B, N, Al, Si, Ti, V, Cr, Fe, Ni, Cu, Ge, Y, Zr, Ru, Mo, Ag, Hf, Ta, W, and Ir.
6. The magnetic recording head of claim 1 , further comprising a spin blocking layer disposed between the shield and the non-magnetic layer, wherein the SOT layer is disposed on a trailing side facing surface of the non-magnetic layer.
7. The magnetic recording head of claim 1 , further comprising a spin blocking layer disposed between the main pole and the non-magnetic layer, wherein the SOT layer is disposed on a trailing side facing surface of the non- magnetic layer.
8. A magnetic recording device comprising the magnetic recording head of claim 1 .
9. The magnetic recording device of claim 8 , further comprising a control unit configured to cause a current to flow through the SOT layer, to cause a first spin current to flow from the SOT layer through the non-magnetic layer to the main pole, and to cause a second spin current to flow from the SOT layer through a second non-magnetic layer to the shield.
10. A magnetic recording head, comprising:
a main pole disposed at a media facing surface (MFS);
a first non-magnetic layer disposed over the main pole, the first non-magnetic layer being disposed at the MFS;
a second non-magnetic layer disposed over the first non-magnetic layer, the second non-magnetic layer being disposed at the MFS, wherein the first non-magnetic layer and the second non-magnetic layer are each individually tapered in shape;
a shield disposed over the second non-magnetic layer; and
a spin orbit torque (SOT) layer disposed over the first non-magnetic layer and the second non-magnetic layer, the SOT layer being recessed a distance of about 20 nm to about 100 nm from the MFS.
11. The magnetic recording head of claim 10 , wherein a ratio of a length of the SOT layer to a thickness of the SOT layer is greater than 1, and wherein the SOT layer comprises undoped BiSb or doped BiSbX, where the dopant is less than about 10 at. %, and where X is a material selected from the group consisting of: B, N, Al, Si, Ti, V, Cr, Fe, Ni, Cu, Ge, Y, Zr, Ru, Mo, Ag, Hf, Ta, W, and Ir.
12. The magnetic recording head of claim 10 , further comprising a spin blocking layer disposed between the first non-magnetic layer and the second non- magnetic layer, the spin blocking layer being disposed at the MFS.
13. The magnetic recording head of claim 12 , the spin blocking layer comprises a material selected from the group consisting of: Ti, Ru, a bilayer of Ti with Ru, Pt, or Mn, a bilayer of Ru with Pt or Mn, and alloys thereof, AlOx, SiN, and MgO, where x is an integer greater than or equal to 1.
14. The magnetic recording head of claim 10 , wherein the first and second non-magnetic layers each individually comprises Cu or Al.
15. A magnetic recording device comprising the magnetic recording head of claim 10 .
16. A magnetic recording head, comprising:
a main pole disposed at a media facing surface (MFS);
a first non-magnetic layer disposed over the main pole, the first non-magnetic layer being disposed at the MFS;
a spin blocking layer disposed over the first non-magnetic layer;
a second non-magnetic layer disposed over the spin blocking layer, the second non-magnetic layer being disposed at the MFS, wherein the first non-magnetic layer and the second non-magnetic layer are each individually tapered in shape;
a trailing shield disposed over the second non-magnetic layer;
a first spin orbit torque (SOT) layer disposed under the first non-magnetic layer; and
a second SOT layer disposed over the second non-magnetic layer, wherein the first SOT layer and the second SOT layer are each individually recessed a distance of about 20 nm to about 100 nm from the MFS.
17. The magnetic recording head of claim 16 , wherein a ratio of a length of the first SOT layer to a thickness of the first SOT layer is greater than 1, wherein a ratio of a length of the second SOT layer to a thickness of the second SOT layer is greater than 1, and wherein the first SOT layer and the second SOT layer each individually comprises BiSb.
18. The magnetic recording head of claim 16 , wherein the first SOT layer is disposed on a main pole facing surface of the first non-magnetic layer, and wherein the second SOT layer is disposed on a trailing shield facing surface of the second non-magnetic layer.
19. The magnetic recording head of claim 16 , wherein the spin blocking layer extends between the first SOT layer and the second SOT layer.
20. A magnetic recording device comprising the magnetic recording head of claim 16 .
21. The magnetic recording device of claim 20 , further comprising a control unit configured to cause a first current to flow through the first SOT layer, to cause a first spin current to flow from the first SOT layer through the first non-magnetic layer to the main pole, to cause a second current to flow through the second SOT layer, and to cause a second spin current to flow from the second SOT layer through the second non- magnetic layer to the trailing shield.
22. A magnetic recording device comprising:
a magnetic recording head, comprising:
a main pole disposed at a media facing surface (MFS);
a shield disposed at the MFS;
a non-magnetic layer disposed between the main pole and the shield, the non-magnetic layer being disposed at the MFS; and
a spin orbit torque (SOT) layer disposed over the non-magnetic layer, the SOT layer being recessed a distance of about 20 nm to about 100 nm from the MFS; and
a control unit configured to cause a current to flow through the SOT layer, to cause a spin current to flow from the SOT layer through the non-magnetic layer to the main pole.
23. A magnetic recording device comprising:
a magnetic recording head, comprising:
a main pole disposed at a media facing surface (MFS);
a shield disposed at the MFS;
a non-magnetic layer disposed between the main pole and the shield, the non-magnetic layer being disposed at the MFS; and
a spin orbit torque (SOT) layer disposed over the non-magnetic layer, the SOT layer being recessed a distance of about 20 nm to about 100 nm from the MFS; and
a control unit configured to cause a current to flow through the SOT layer, to cause a spin current to flow from the SOT layer through the non-magnetic layer to the shield.