Structure to achieve sensitivity and linear density in tunneling GMR heads using orthogonal magnetic alignments

1. A magnetoresistive read sensor comprising:

first and second electrodes; and

a stack positioned between the electrodes, the stack comprising a first free layer and a second free layer, and a tunneling barrier positioned between the first and second free layers;

wherein a current is passed between the first and second free layers of the stack and the amount of current passing through the first and second free layer changes based upon the magnetization orientation of the first and second free layers relative to each other.

2. The sensor of claim 1 , wherein the electrodes are configured to be shield members.

3. The sensor of claim 1 , wherein the stack further comprises cap layers positioned between the free layers and the electrodes.

4. The sensor of claim 2 , wherein the stack comprises first and second sides aligned in the direction current passes between the free layers and in a direction parallel to a track of a memory media from which the sensor reads, and front and rear sides aligned perpendicular to a surface of the memory media, the front side being positioned adjacent the memory media.

5. The sensor of claim 4 , further comprising a biasing member positioned adjacent the stack to bias magnetization vectors of the first free layer orthogonal to magnetization vectors of the second free layer.

6. The sensor of claim 5 , wherein the biasing member is positioned adjacent the rear side of the stack.

7. The sensor of claim 6 , wherein the biasing member comprises a soft magnetic layer coupled with an AFM layer.

8. The sensor of claim 5 , wherein the biasing member comprises an AFM layer positioned in the stack adjacent each of the free layers.

9. The sensor of claim 1 , wherein the free layers are biased orthogonal to each other due to their shape induced anisotropy.

10. The sensor of claim 1 , wherein the free layers are biased by another in-stack soft biased layer of AFM/FM pair on top and underneath the free layers.

11. The sensor of claim 4 , wherein the stack further comprises third and fourth sides, and the shield members are configured to shield the first and second sides of the stack and a portion of the third and fourth sides of the stack.

12. The sensor of claim 5 , wherein the biasing member is insulating.

13. The sensor of claim 1 , wherein the tunneling barrier is configured to be a non-metallic spacer.

14. The sensor of claims 1 , wherein the tunneling barrier is configured to be an insulating layer with a nanobridge in the insulating layer connecting the first and second free layers.

15. The sensor of claim 1 , wherein the tunneling barrier is configured to be an oxide pinhole mesh.

16. The sensor of claim 1 , wherein the tunneling barrier is configured to be a periodically modulated spacer having a superlattice structure with n repeats of a bilayer conductor.

17. The sensor of claim 1 , wherein the free layer is configured to be a Heusler magnetic layer comprising materials from the group consisting of Co 2 MnGe, CoMnSi, Co 2 MnAl, Co 2 MnSn, Co 2 MnGa, NiMnSb, PtMnSb, CoMnSb, FeMnSb, CrMnSb.

18. A magnetoresistive sensor capable of sensing changes in magnetic fields from a memory media track, comprising:

first and second electrodes;

first and second free layers each having a magnetization orientation, the magnetization orientation of the layers being orthogonal to each other, and

an insulation layer positioned between the first and second free layers;

wherein changes in the magnetic fields of the memory media track create a change in the amount of current passing between the first and second electrodes and thereby the first and second free layers based upon the magnetization orientation of the first and second free layers relative to each other.

19. The sensor of claim 18 , further comprising a biasing member capable of biasing the magnetization orientation of at least one of the first and second free layers.

20. The sensor of claim 19 , wherein the biasing member is positioned above the stack relative to the memory media track.

21. The sensor of claim 18 , wherein the sense current travels through the stack in a direction substantially parallel to the memory media track.

22. The sensor of claim 18 , wherein the insulating layer is configured to be a non-metallic spacer.

23. A magnetoresistive read sensor comprising: first and second electrodes, a stack positioned between the electrodes, the stack comprising a first free layer and a second free layer, and a tunneling barrier positioned between the first and second free layers;

a biasing member positioned adjacent the stack to bias a first magnetization vector of the first free layer orthogonal to a second magnetization vector of the second free layer; and

wherein a current is passed between the first and second free layers of the stack and the amount of current passing through the first and second free layer changes based upon the magnetization orientation of the first and second free layers relative to each other.

24. The sensor of claim 23 , wherein the tunneling barrier is configured to be a non-metallic spacer.

25. The sensor of claim 23 , further comprising an air bearing surface and a rear surface, wherein the biasing member is positioned adjacent the rear surface.

26. The sensor of claim 25 , wherein the biasing member comprises an AFM layer positioned in the stack adjacent each of the free layers.

27. The sensor of claim 23 , wherein the free layers are biased orthogonal to each other due to their shape induced anisotropy.

28. The sensor of clam 23 , wherein the free layers are biased by another in stack soft biased layer of AFM/FM pair on top and underneath the free layers.

29. The sensor of claims 23 , wherein the tunneling barrier is configured to be an insulating layer with a nanobridge in the insulating layer connecting the first and second free layers.

30. The sensor of claim 23 , wherein the tunneling barrier is configured to be an oxide pinhole mesh.