Solid state microwave generator

Patent metadata

Field	Value
Publication number	US-10601368-B2
Application number	US-201615237081-A
Country	US
Kind code	B2
Filing date	Aug 15, 2016
Priority date	May 19, 2016
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A spin torque oscillation generator includes a spin reference layer and a spin oscillation layer. The spin reference layer has a first magnetization direction. The spin reference layer is configured to receive a current and generate a spin-polarized current. The spin oscillation layer has a second magnetization direction. The second magnetization direction is different than the first magnetization direction. The spin oscillation layer is configured to receive the spin-polarized current from the spin reference layer. The spin-polarized current generates a spin torque based on the second magnetization direction of the spin oscillation layer. The spin torque generates a spin torque output signal.

First claim

What is claimed is:

1. An apparatus, comprising:
a first spin reference layer comprising L1 0 -phased hard magnetic alloy and having a first magnetization direction normal to the layer, the first spin reference layer configured to receive a current normal to the layer and pass electrons having a spin direction substantially similar to the first magnetization direction that generates a spin-polarized current; and
a first spin oscillation layer comprising a negative magnetic anisotropy material and having a second magnetization direction, wherein the second magnetization direction is different than the first magnetization direction, wherein the first spin oscillation layer is configured to receive the spin-polarized current from the first spin reference layer, wherein the spin-polarized current generates a spin torque output signal based on the second magnetization direction of the first spin oscillation layer;
a second spin reference layer separated from the first spin oscillation layer through an exchange breaking layer comprising face-centered cubic (FCC) structure, wherein the second spin reference has a third magnetization direction normal to the layer, the second spin reference layer configured to receive the spin torque output signal from the first spin oscillation layer and pass electrons having spin direction substantially similar to the third magnetization direction that generates another spin-polarized current; and
a second spin oscillation layer having a fourth magnetization direction, wherein the fourth magnetization direction is different than the third magnetization direction, wherein the second spin oscillation layer is configured to receive the another spin-polarized current from the second spin reference layer, wherein the another spin-polarized current generates another spin torque output signal based on the fourth magnetization direction of the second spin oscillation layer, and wherein the another spin torque output signal generates another microwave output signal.

2. The apparatus of claim 1 further comprising:
a second exchange breaking layer configured to magnetically decouple the first spin reference layer from the first spin oscillation layer.

3. The apparatus of claim 2 , wherein the second exchange breaking layer is selected from the group consisting of a silver-alloy, a copper-alloy, and a gold-alloy.

4. The apparatus of claim 1 , wherein a difference between a magnetization angle of the first magnetization direction and the second magnetization direction ranges between 0° and 90°.

5. The apparatus of claim 1 , wherein a frequency associated with the microwave output signal is adjustable through application of an external magnetic field to the apparatus.

6. The apparatus of claim 5 , wherein the external magnetic field partially overlaps the first spin oscillation layer, and wherein the second magnetization direction is aligned in a same magnetization direction as the external magnetic field.

7. The apparatus of claim 1 , wherein a frequency associated with the microwave output signal is adjustable by varying a density associated with the current.

8. The apparatus of claim 1 , comprising a transmitter coupled to the second spin oscillation layer, wherein the transmitter is configured to transmit the microwave output signal.

9. The apparatus of claim 1 , wherein the first spin reference layer generates a spin-polarized current by filtering electrons having a first spin direction substantially similar to the first magnetization direction and scattering electrons having a second spin direction substantially opposite to the first magnetization direction.

10. The apparatus of claim 1 , wherein the first spin reference layer is selected from the group consisting of a copper-platinum alloy, and an iron-platinum alloy.

11. The apparatus of claim 1 , wherein the first spin oscillation layer is selected from the group consisting of a nickel-alloy, an iron-alloy, and a cobalt-alloy.

12. A system, comprising:
a first spin torque oscillation generator and a second spin torque oscillation generator, wherein an insulator comprising oxide is positioned between the first spin torque oscillation generator and the second spin torque oscillation generator, wherein the insulator electrically insulates the first spin torque oscillation generator from the second spin torque oscillation generator, and wherein each spin torque oscillation generator comprises:
a spin reference layer comprising L1 0 -phased hard magnetic alloy and having a first magnetization direction normal to the layer, the spin reference layer configured to receive a current normal to the layer and generate a spin-polarized current from electrons having a spin direction substantially similar to the first magnetization direction; and
a spin oscillation layer comprising a negative magnetic anisotropy material and having a second magnetization direction, wherein the second magnetization direction is different than the first magnetization direction, wherein the spin oscillation layer is configured to receive the spin-polarized current from the spin reference layer, wherein the spin-polarized current generates a spin torque based on the second magnetization direction of the spin oscillation layer, and wherein the spin torque generates a microwave output signal,
the first spin torque oscillation generator stacked with the second spin torque oscillation generator with the spin oscillation layer of the first spin torque oscillation generator closer to the spin reference layer of the second spin torque oscillation generator than to any other layer of the second spin torque oscillation generator,
wherein a first magnetization angle between the first magnetization direction and the second magnetization direction of the first spin torque oscillation generator and a second magnetization angle between the first magnetization direction and the second magnetization direction of the second spin torque oscillation generator are configured such that the microwave output signal of each of the first and second spin torque oscillation generators are substantially additive; and

a transmitter coupled to the first spin torque oscillation generator and the second spin torque oscillation generator.

13. The system of claim 12 , wherein first magnetization angle is substantially equal to the second magnetization angle.

14. The system of claim 12 , wherein each of the first magnetization angle and the second magnetization angle ranges between 0° and 90°.

15. The apparatus of claim 12 , wherein each of the first and second spin torque oscillation generators comprises an exchange breaking layer configured to magnetically decouple the spin reference layer from the spin oscillation layer.

16. The apparatus of claim 12 , comprising at least one magnetic field generator configured to generate a magnetic field at least partially overlapping the spin oscillation layer of each of the first and second spin torque oscillation generators, and wherein the second magnetization direction is determined by the magnetic field.

17. The apparatus of claim 16 , wherein each of the first and second spin torque oscillation generators comprises a magnetic field generator, and wherein each of the magnetic field generators generate a magnetic field configured to substantially align the second magnetization direction of each of the spin oscillation layers.

18. The apparatus of claim 12 further comprising a third spin torque oscillation generator, wherein the third spin torque oscillation generator comprises a spin reference layer and a spin os

Assignees

• Seagate Technology Llc

Inventors

• Lu Bin

Classifications

• H03B2200/0076

  Power combination of several oscillators oscillating at the same frequency · CPC title

• H03B15/006 Primary

  using spin transfer effects or giant magnetoresistance · CPC title

• H03B5/00 Primary

  Generation of oscillations using amplifier with regenerative feedback from output to input (H03B9/00, H03B15/00 take precedence) · CPC title