IP Library Granted Patent US 7,898,844
Granted Patent B2
US 7,898,844 · App. 12/367,966 · Granted Mar 1, 2011

Magnetic tunnel junction and memristor apparatus

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Quick Facts
Patent No.
US 7,898,844
App. No.
12/367,966
Granted
Mar 1, 2011
Kind
B2
Abstract

A magnetic memory device includes a magnetic tunnel junction having a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation and a memristor solid state element electrically coupled to the magnetic tunnel junction. The memristor has a device response that is an integrated voltage versus an integrated current.

Claims (25)

1. A magnetic memory device comprising:

a magnetic tunnel junction comprising a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation; and

a memristor solid state element electrically coupled to the magnetic tunnel junction, the memristor having a device response that is an integrated voltage versus an integrated current, the memristor solid state element comprises a varying resistance layer, the varying resistance layer comprising a high resistance layer and a low resistance layer comprising oxygen vacancies, the varying resistance layer having a thickness of 10 nanometers or less.

2. A magnetic memory device according to claim 1 , wherein the memristor solid state element is in serial electrical connection with the magnetic tunnel junction.

3. A magnetic memory device according to claim 1 , wherein a thickness of the high resistance layer and a thickness of the low resistance layer change as a function of an amount of charge passing thorough the memristor solid state element.

4. A magnetic memory device according to claim 1 , wherein the memristor solid state element measures total current passing through the magnetic tunnel junction.

5. A method of measuring magnetic fluctuations in a magnetic tunnel junction comprising:

passing a current through a magnetic tunnel junction and a memristor solid state element, the memristor solid state element measures a total memristor current value passing through the memristor solid state element, the memristor solid state element comprises a varying resistance layer, the varying resistance layer comprising a high resistance layer and a low resistance layer comprising oxygen vacancies; and

determining a magnetic fluctuation value by subtracting a total baseline current value from the total memristor current value.

6. A method according to claim 5 , wherein the total baseline current value is determined when the magnetic tunnel junction possesses a constant high resistance saturation state.

7. A method according to claim 5 , wherein the total baseline current value is determined when the magnetic tunnel junction possesses a constant low resistance saturation state.

8. A method according to claim 6 , wherein the total memristor current value is less than the total baseline current value.

9. A method according to claim 7 , wherein the total memristor current value is greater than the total baseline current value.

10. A method according to claim 5 , further comprising reading the total memristor current value with a sense amplifier in electrical connection with the memristor solid state device.

11. A method according to claim 10 , wherein the sense amplifier is in parallel electrical connection with the memristor solid state device.

12. A method according to claim 10 , wherein the sense amplifier is in serial electrical connection with the memristor solid state device.

13. A method according to claim 10 , further comprising resetting the memristor solid state device by passing a current through the memristor solid state device in a direction opposing the passing step current direction.

14. A method according to claim 10 , wherein the varying resistance layer has a thickness of 10 nanometers or less.

15. A method according to claim 14 , wherein a thickness of the high resistance layer and a thickness of the low resistance layer change as a function of an amount of charge passing thorough the memristor solid state element.

16. A method according to claim 10 , wherein the memristor solid state element measures total current passing through the magnetic tunnel junction.

17. A method of monitoring power consumed by an electrical device comprising:

passing current through a memristor solid state element and an electrical device, the memristor solid state element measuring the current passing through the memristor solid state element and forming a memristance value, the memristor solid state element comprises a varying resistance layer, the varying resistance layer comprising a high resistance layer and a low resistance layer comprising oxygen vacancies, the varying resistance layer having a thickness of 10 nanometers or less; and

reading the memristance value to determine the power consumed by the electrical device.

18. The method according to claim 17 , wherein the memristor solid state element and an electrical device are in serial electrical connection and the current is provided with a constant voltage source.

19. The method according to claim 17 , wherein the memristor solid state element and an electrical device are in parallel electrical connection and the current is provided with a constant current source.

Assignments (6)
RELEASE OF SECURITY INTEREST Recorded Jul 23, 2025
From: THE BANK OF NOVA SCOTIA
To: SEAGATE TECHNOLOGY PUBLIC LIMITED COMPANY; SEAGATE TECHNOLOGY; SEAGATE TECHNOLOGY HDD HOLDINGS; I365 INC.; SEAGATE TECHNOLOGY LLC; SEAGATE TECHNOLOGY INTERNATIONAL; SEAGATE HDD CAYMAN; SEAGATE TECHNOLOGY (US) HOLDINGS, INC.
Reel/Frame 072193/0001 →
TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENT RIGHTS Recorded Jul 19, 2013
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT AND SECOND PRIORITY REPRESENTATIVE
To: SEAGATE TECHNOLOGY LLC; EVAULT INC. (F/K/A I365 INC.); SEAGATE TECHNOLOGY INTERNATIONAL; SEAGATE TECHNOLOGY US HOLDINGS, INC.
Reel/Frame 030833/0001 →
SECURITY AGREEMENT Recorded Mar 24, 2011
From: SEAGATE TECHNOLOGY LLC
To: THE BANK OF NOVA SCOTIA, AS ADMINISTRATIVE AGENT
Reel/Frame 026010/0350 →
RELEASE Recorded Jan 19, 2011
From: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
To: SEAGATE TECHNOLOGY HDD HOLDINGS; MAXTOR CORPORATION; SEAGATE TECHNOLOGY LLC; SEAGATE TECHNOLOGY INTERNATIONAL
Reel/Frame 025662/0001 →
SECURITY AGREEMENT Recorded May 15, 2009
From: MAXTOR CORPORATION; SEAGATE TECHNOLOGY LLC; SEAGATE TECHNOLOGY INTERNATIONAL
To: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT AND FIRST PRIORITY REPRESENTATIVE; WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT AND SECOND PRIORITY REPRESENTATIVE
Reel/Frame 022757/0017 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 11, 2009
From: WANG, XIAOBIN; CHEN, YIRAN; WANG, ALAN; XI, HAIWEN; ZHU, WENZHONG; LI, HAI; LIU, HONGYUE
To: SEAGATE TECHNOLOGY LLC
Reel/Frame 022242/0324 →