Nitrogen-vacancy nanocrystal magnetic source sensor

• US 9,245,551 B2
• Filed: 03/18/2015
• Issued: 01/26/2016
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: El Hallak, Fadi, Mooney, Marcus B.
• Primary Examiner(s): Cao, Allen T
• Application Number:
  US14/661,558
• Publication Number:
  US 20150269957A1
• Time in Patent Office: 314 Days
• Field of Search: 360/88
• US Class Current: 1/1
• CPC Class Codes: G01R 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: G11B 19/00 Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
• CPC Class Codes: G11B 5/455 Arrangements for functional testing of heads; Measuring arrangements for heads

Abstract

A sensor may be configured with a nanocrystal that has a nitrogen-vacancy. The nanocrystal can be positioned proximal a magnetic source, mount, and articulable stage. Various embodiments configure the articulable stage configured to align the nanocrystal and the magnetic source along a common axis to sense magnetic fields about the magnetic source with a sub-nanometer resolution.

Claims

1. An apparatus comprising a nanocrystal comprising a nitrogen-vacancy, the nanocrystal positioned proximal a magnetic source and a mount, the mount configured to position the nanocrystal to sense magnetic fields about the magnetic source with a sub-nanometer resolution.

2. The apparatus of claim 1, wherein the mount is rigid.

3. The apparatus of claim 1, wherein the mount is flexible.

4. The apparatus of claim 1, wherein the nanocrystal comprises a carbon lattice with at least one carbon atom bound to at least one nitrogen atom.

5. The apparatus of claim 1, wherein nanocrystal has a ground spin state of 1.

6. The apparatus of claim 1, wherein the nanocrystal is suspended between a detector and the magnetic source by the mount.

7. The apparatus of claim 1, wherein first and second frequency sources are positioned on opposite sides of the nanocrystal, the frequency sources respectively emitting signals with different frequencies.

8. The apparatus of claim 7, wherein the first frequency source is positioned along a first plane in alignment with the nanocrystal and the second frequency source is positioned along a second plane in alignment with the nanocrystal, the first and second planes being different.

9. The apparatus of claim 1, wherein the mount comprises an actuator configured to move the nanocrystal relative to the magnetic source.

10. An apparatus comprising a nanocrystal comprising a nitrogen-vacancy, the nanocrystal positioned proximal a data writer and an articulable stage, the articulable stage configured to align the nanocrystal and the data writer along a common axis to sense magnetic fields about the data writer with a sub-nanometer resolution.

11. The apparatus of claim 10, wherein the data writer has an air bearing surface (ABS) surface area of less than one nanometer.

12. The apparatus of claim 10, wherein the common axis extends through a center of the nanocrystal.

13. The apparatus of claim 10, wherein the nanocrystal is separated from and disposed between the articulable stage and a plurality of detectors.

14. The apparatus of claim 10, wherein the nanocrystal contacts the articulable stage and the data writer is suspended over the nanocrystal by a mount.

15. A method comprising:

positioning a nanocrystal proximal a data writer and an articulable stage via a mount, the nanocrystal comprising a nitrogen-vacancy; and

sensing magnetic fields and field gradients about the data writer with sub-nanometer resolution.

16. The method of claim 15, wherein the articulable stage is moved to align the nitrogen-vacancy of the nanocrystal with the data writer along a common axis.

17. The method of claim 15, wherein the mount moves during the sensing step.

18. The method of claim 15, wherein a first source emits a radio frequency toward the nanocrystal and a second source emits an optical pattern onto the nanocrystal.

19. The method of claim 15, wherein the sensed magnetic fields and field gradients identify a defect in the data writer.

20. The method of claim 15, wherein the sensed magnetic fields and field gradients differ from a magnetic model prediction.