IP Library Granted Patent US 11,990,868
Granted Patent B2
US 11,990,868 · App. 17/435,577 · Granted May 21, 2024

Spin hall oscillator

Inventors: Nam Hai Pham (Tokyo, JP); Takanori Shirokura (Tokyo, JP)
Assignee: TOKYO INSTITUTE OF TECHNOLOGY
H03B15/006G01R33/093G11B5/3909H10N50/10H10N50/85H10N52/80
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Quick Facts
Patent No.
US 11,990,868
App. No.
17/435,577
Granted
May 21, 2024
Kind
B2
Abstract

An oscillator includes a spin current source, and a free layer coupled to the spin current source. The free layer has a magnetization hard axis that is parallel to a quantization axis of a spin current injected by the spin Hall effect of the spin current source.

Claims (48)

1. A two-terminal spin Hall oscillator comprising:

a spin current source; and

a free layer coupled to the spin current source,

wherein the free layer has a magnetization hard axis that is parallel to a quantization axis of a spin current injected due to a spin Hall effect of the spin current source.

2. A two-terminal spin Hall oscillator comprising:

a spin current source;

a magnetic tunnel junction (MTJ) device comprising a free layer coupled to the spin current source, a tunnel barrier layer, and a pinned layer; and

an electrode coupled to the MTJ device,

wherein the spin Hall oscillator has a structure in which the spin current source is short-circuited to the electrode via a resistor element coupled in parallel with the MTJ device,

and wherein the free layer and the pinned layer of the MTJ device each have a magnetization hard axis parallel to a quantization axis of a spin current injected by a spin Hall effect of the spin current source.

3. A two-terminal spin Hall oscillator comprising:

a spin current source;

a MTJ device comprising a free layer coupled to the spin current source, a tunnel barrier layer, and a pinned layer; and

an electrode coupled to the MTJ device,

wherein the free layer and the pinned layer of the MTJ device each have a magnetization hard axis parallel to a quantization axis of a spin current injected by a spin Hall effect of the spin current source.

4. A spin Hall oscillator comprising a plurality of spin Hall oscillators having the same structure, wherein the plurality of spin Hall oscillators are electrically or magnetically coupled so as to operate in synchronization, and wherein

at least of the plurality of spin Hall oscillators is the two-terminal spin Hall oscillator according to claim 1 .

5. The spin Hall oscillator comprising a plurality of spin Hall oscillators having the same structure or a different structure,

wherein the plurality of spin Hall oscillators are electrically or magnetically coupled so as to operate in synchronization, and wherein

at least of the plurality of spin Hall oscillators is the two-terminal spin Hall oscillator according to claim 2 .

6. The spin Hall oscillator comprising a plurality of spin Hall oscillators having the same structure or a different structure,

wherein the plurality of spin Hall oscillators are electrically or magnetically coupled so as to operate in synchronization, and wherein

at least of the plurality of spin Hall oscillators is the two-terminal spin Hall oscillator according to claim 1 .

7. The spin Hall oscillator according to claim 1 , wherein the spin current source includes one or a plurality of elements selected from a group consisting of Pt, Ta, W, Ir, 3d, 4d, 5d, 4f, and 5f elements that provide a strong spin orbital interaction.

8. The spin Hall oscillator according to claim 2 , wherein the spin current source includes one or a plurality of elements selected from a group consisting of Pt, Ta, W, Ir, 3d, 4d, 5d, 4f, and 5f elements that provide a strong spin orbital interaction.

9. The spin Hall oscillator according to claim 3 , wherein the spin current source includes one or a plurality of elements selected from a group consisting of Pt, Ta, W, Ir, 3d, 4d, 5d, 4f, and 5f elements that provide a strong spin orbital interaction.

10. The spin Hall oscillator according to claim 1 , wherein the spin current source includes one or a plurality of materials from among topological insulators such as BiSb, Bi2Se3, Bi2Te3, and (Bi,Sb)2Te3.

11. The spin Hall oscillator according to claim 2 , wherein the spin current source includes one or a plurality of materials from among topological insulators such as BiSb, Bi2Se3, Bi2Te3, and (Bi,Sb)2Te3.

12. The spin Hall oscillator according to claim 3 , wherein the spin current source includes one or a plurality of materials from among topological insulators such as BiSb, Bi2Se3, Bi2Te3, and (Bi,Sb)2Te3.

13. The spin Hall oscillator according to claim 1 , wherein the free layer is configured as a magnetic layer including one or a plurality of elements selected from a group consisting of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.

14. The spin Hall oscillator according to claim 2 , wherein the free layer is configured as a magnetic layer including one or a plurality of elements selected from a group consisting of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.

15. The spin Hall oscillator according to claim 3 , wherein the free layer is configured as a magnetic layer including one or a plurality of elements selected from a group consisting of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.

16. The spin Hall oscillator according to claim 2 , wherein the pinned layer is configured as a magnetic layer including one or a plurality of elements selected from a group consisting of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.

17. The spin Hall oscillator according to claim 3 , wherein the pinned layer is configured as a magnetic layer including one or a plurality of elements selected from a group consisting of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.

18. The spin Hall oscillator according to claim 2 , wherein the tunnel barrier layer is configured as an insulator formed of a metal oxide including one or a plurality of elements selected from a group consisting of Ga, Al, Mg, Hf, and Zr.

19. The spin Hall oscillator according to claim 3 , wherein the tunnel barrier layer is configured as an insulator formed of a metal oxide including one or a plurality of elements selected from a group consisting of Ga, Al, Mg, Hf, and Zr.

20. The spin Hall oscillator according to claim 1 , wherein the free layer is configured as a magnetic layer having a magnetization hard axis provided by one or more from shape magnetic anisotropy, uniaxial crystal magnetic anisotropy, interfacial magnetic anisotropy, and induced magnetic anisotropy provided by film formation in a magnetic field, annealing in a magnetic field, or oblique deposition, such that the magnetization hard axis is parallel to a quantization axis of a spin current injected by a spin Hall effect of the spin current source.

21. The spin Hall oscillator according to claim 2 , wherein the free layer is configured as a magnetic layer having a magnetization hard axis provided by one or more from shape magnetic anisotropy, uniaxial crystal magnetic anisotropy, interfacial magnetic anisotropy, and induced magnetic anisotropy provided by film formation in a magnetic field, annealing in a magnetic field, or oblique deposition, such that the magnetization hard axis is parallel to a quantization axis of a spin current injected by a spin Hall effect of the spin current source.

22. The spin Hall oscillator according to claim 3 , wherein the free layer is configured as a magnetic layer having a magnetization hard axis provided by one or more from shape magnetic anisotropy, uniaxial crystal magnetic anisotropy, interfacial magnetic anisotropy, and induced magnetic anisotropy provided by film formation in a magnetic field, annealing in a magnetic field, or oblique deposition, such that the magnetization hard axis is parallel to a quantization axis of a spin current injected by a spin Hall effect of the spin current source.

23. The spin Hall oscillator according to claim 1 , configured to be driven using an ordinary driving method in which a driving current is directly applied, or a pulse excitation oscillation method in which, in a first stage, a large pulse current on the order of approximately 1 ns is applied.

24. The spin Hall oscillator according to claim 2 , configured to be driven using an ordinary driving method in which a driving current is directly applied, or a pulse excitation oscillation method in which, in a first stage, a large pulse current on the order of approximately 1 ns is applied.

25. The spin Hall oscillator according to claim 3 , configured to be driven using an ordinary driving method in which a driving current is directly applied, or a pulse excitation oscillation method in which, in a first stage, a large pulse current on the order of approximately 1 ns is applied.

26. A magnetic recording device comprising the spin Hall oscillator according to claim 1 , wherein microwaves generated by the spin Hall oscillator are used to assist recording.

27. A magnetic recording device comprising the spin Hall oscillator according to claim 2 , wherein microwaves generated by the spin Hall oscillator are used to assist recording.

28. A magnetic recording device comprising the spin Hall oscillator according to claim 3 , wherein microwaves generated by the spin Hall oscillator are used to assist recording.

29. A computer provided with an artificial neuron comprising the spin Hall oscillator according to claim 1 .

30. A computer provided with an artificial neuron comprising the spin Hall oscillator according to claim 2 .

31. A computer provided with an artificial neuron comprising the spin Hall oscillator according to claim 3 .

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 7, 2021
From: PHAM, NAM HAI; SHIROKURA, TAKANORI
To: TOKYO INSTITUTE OF TECHNOLOGY
Reel/Frame 057400/0250 →
Priority Claims (1)
JP 2019-037682 · Mar 1, 2019 · national
Continuity (1)
Related Publication 20220060149A1 · Feb 24, 2022