Magnetic memory elements using 360° walls

• US 6,906,369 B2
• Filed: 02/10/2004
• Issued: 06/14/2005
• Est. Priority Date: 02/10/2003
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Ross, Caroline A., Castano, Fernando J.
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): TRAN, MAI HUONG C
• Application Number:
  US10/775,600
• Publication Number:
  US 20040211996A1
• Time in Patent Office: 490 Days
• Field of Search: 428/692, 428/694, 428/900, 365/129, 365/158, 365/173
• US Class Current: 257/295
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/5607 using magnetic storage elements
• CPC Class Codes: G11C 19/0808 using magnetic domain propagation
• CPC Class Codes: G11C 21/00 Digital stores in which the information circulates continuouslystepwise G11C19/00
• CPC Class Codes: G11C 2211/5615 Multilevel magnetic memory cell using non-magnetic non-conducting interlayer, e.g. MTJ
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/32 Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Abstract

A magnetic-ring structure includes at least two states, and at least one twisted state that includes a 360° domain wall that can exist over a wide range of applied fields.

Claims

1. A magnetic-ring structure comprising at least two states and at least one twisted state that includes a 360°

domain wall that can exist over a wide range of applied fields.

2. The magnetic-ring structure of claim 1, wherein said at least two states comprise at least one onion state.

3. The magnetic-ring structure of claim 1, wherein said at two states comprise at least one vortex state.

4. The magnetic-ring structure of claim 1, wherein said at least one twisted state comprises two states.

5. The magnetic-ring structure of claim 1, wherein said at least one twisted state comprises four states.

6. A method of operating a magnetic-ring structure comprising:

providing said magnetic-ring structure with at least two states; and

providing at one twisted state that includes a 360°

domain wall that can exist over a wide range of applied fields.

7. The method of claim 6, wherein said at least two more states comprise at least one onion state.

8. The method of claim 6, wherein said at least two states comprise at least one vortex state.

9. The method of claim 6, wherein said at least one twisted state comprises four states.

10. The method of claim 6, wherein said at least one twisted state comprises two states.