Data Storage Device with Phase Lock Spin-Torque Oscillation Stabilization

• US 20160027456A1
• Filed: 07/27/2015
• Published: 01/28/2016
• Est. Priority Date: 07/25/2014
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Gao, Kaizhong
• Granted Patent: US 9,368,135 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G11B 2005/0024 Microwave assisted recording
• CPC Class Codes: G11B 5/11 Shielding of head against electric or magnetic fields
• CPC Class Codes: G11B 5/127 Structure or manufacture of heads, e.g. inductive
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/313 Disposition of layers
• CPC Class Codes: G11B 5/3146 magnetic layers
• CPC Class Codes: G11B 5/315 Shield layers on both sides of the main pole, e.g. in perpendicular magnetic heads
• CPC Class Codes: G11B 5/35 having vibrating elements
• CPC Class Codes: G11B 5/6082 Design of the air bearing surface

Abstract

A data storage device can be configured at least with a first spin-torque oscillator disposed between and contacting a write pole and a shield on an air bearing surface. A second spin-torque oscillator can be disposed between and contact the write pole and shield with the second spin-torque oscillator separated from the air bearing surface by a first stabilization distance and from the first spin-torque oscillator by a second stabilization distance. The first and second spin-torque oscillators can be configured to magnetostatically couple and phase lock to produce a single microwave frequency in response to a bias field.

Claims

1. An apparatus comprising:

a first spin-torque oscillator (STO) disposed between and contacting a write pole and a shield on an air bearing surface (ABS); and

a second STO disposed between and contacting the write pole and shield, the second STO separated from the ABS by a first stabilization distance and from the first STO by a second stabilization distance, the first and second STOs configured to magnetostatically couple and phase lock to produce a single microwave frequency in response to a bias field.

2. The apparatus of claim 1, wherein the first and second STOs each contact a trailing edge of the write pole and occupy less than all of a write gap between the write pole and shield

3. The apparatus of claim 1, wherein the single microwave frequency is 5-50 GHz.

4. The apparatus of claim 1, wherein the bias field is 5-15 kOe that passes through the write pole, shield, and each STO.

5. The apparatus of claim 1, wherein the shield has a height that is less than an aggregate height of the first STO, second STO, and first stabilization distance, each height measured perpendicular to the ABS.

6. The apparatus of claim 1, wherein the shield has a height that is greater than an aggregate height of the first STO, second STO, and first stabilization distance, each height measured perpendicular to the ABS.

7. An apparatus comprising:

a first spin-torque oscillator (STO) disposed between and contacting a write pole and a shield on an air bearing surface (ABS); and

a second STO disposed between and contacting the write pole and shield, the second STO separated from the ABS by a first stabilization distance and from the first STO by a second stabilization distance, each STO comprising an interlayer separating an injector layer from a generating layer, the first STO configured differently than the second STO to magnetostatically couple and phase lock the first and second STOs to produce a single microwave frequency in response to a bias field.

8. The apparatus of claim 7, wherein the interlayer of the first STO is offset from the interlayer of the second STO, the offset measured parallel to the ABS.

9. The apparatus of claim 7, wherein the respective generating layers of the STOs have different widths, each width measured parallel to the ABS.

10. The apparatus of claim 7, wherein the write pole and shield each have tapered surfaces extending from the ABS at non-normal angles.

11. The apparatus of claim 7, wherein the first STO oscillates at a different frequency than the second STO

12. The apparatus of claim 7, wherein a width of the injector layer of the first STO is different than a width of the generating layer of the first STO, each width measured parallel to the ABS.

13. The apparatus of claim 7, wherein the first STO has a first length that is less than a second length of a trailing edge of the write pole, each length measured parallel to the ABS.

14. The apparatus of claim 7, wherein the generating layer of the first STO has a width equal to an aggregate width of the interlayer and injector layer, each width measured parallel to the ABS.

15. The apparatus of claim 7, wherein the generating layer of the first STO comprises a different material than the generating layer of the second STO.

16. A method comprising:

positioning a first spin-torque oscillator (STO) between and contacting a write pole and a shield on an air bearing surface (ABS);

disposing a second STO between and contacting the write pole and shield, the second STO separated from the ABS by a first stabilization distance and from the first STO by a second stabilization distance; and

passing a bias field through each STO to magnetostatically couple and phase lock the first and second STOs to generate a single microwave frequency.

17. The method of claim 16, wherein the single microwave frequency alters a data bit on an adjacent data storage medium.

18. The method of claim 16, wherein the phase lock of the STOs produces a single stable oscillation and the single microwave frequency.

19. The method of claim 16, wherein the single microwave frequency is produced concurrently with programming of one or more data bits with the write pole.

20. The method of claim 16, wherein the bias field passes through the STOs in parallel.