# US 2015/0146469 A1 · Magnetic memory devices and systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0146469 A1 - Document ID: US20150146469A1 - Status: Published application - Kind: A1 - Application number: 14/523,663 - Filed: 2014-10-24 - Published: 2015-05-28 - Earliest claimed: 2008-05-23 - Assignees: Christoforos Moutafis - Inventors: Christoforos MOUTAFIS; Stavros KOMINEAS - Web page: https://patentgrep.com/patent/US20150146469A1 ## CPC - G11C 19/0841: {using electric current} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - G11C 11/16: using elements in which the storage effect is based on magnetic spin effect - G11C 11/1673: {Reading or sensing circuits or methods} - G11C 11/1675: {Writing or programming circuits or methods} - G11C 11/5607: {using magnetic storage elements} - G11C 19/08: using thin films in plane structure - G11C 19/0866: {Detecting magnetic domains} - H10N 50/10: Magnetoresistive devices - G11C: STATIC STORES (semiconductor memory devices H10B) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A method of storing one or more bits of information comprising: forming a magnetic bubble; and storing a said bit of information encoded in a typology of a domain wall of said magnetic bubble. Preferably a bit is encoded using a symmetric topological state of the domain wall and a topological state including at least one winding rotation of a magnetisation vector of the domain wall. Preferably the magnetic bubble is confined in an island of magnetic material, preferably of maximum dimension less than 1 μm. ## Claims ### Claim 1 A method of storing one or more bits of information, the method comprising: forming a magnetic bubble; and storing a said bit of information encoded in a topology of a domain wall of said magnetic bubble. ### Claim 2 (depends on 1) A method as claimed in claim 1 wherein said storing comprises storing said bit encoded using S=O and S=1 status of said domain wall, in particular wherein said S=1 states of said domain wall, wherein said S=1 state comprises a symmetric state of said domain wall and said S=O states includes at least one winding rotation of a magnetisation vector of said domain wall in moving along a border of said bubble defined by said domain wall. ### Claim 3 (depends on 1) A method as claimed in claim 1 further comprising confining said magnetic bubble in an island of magnetic material. ### Claim 4 (depends on 3) A method as claimed in claim 3 wherein said confining is such that said bubble is substantially stable without application of a bias field. ### Claim 5 (depends on 1) A method as claimed in claim 1, further comprising changing a value of a said bit of information by applying to said magnetic bubble a magnetic field gradient pulse or electrical current excitation. ### Claim 6 A magnetic storage device for storing one or more bits of information, the device comprising: a plurality of islands of magnetic material; a plurality of magnetic bubbles, at least one per said island; wherein said bits of information are stored encoded in a topology of a domain wall of said magnetic bubble. ### Claim 7 (depends on 6) A magnetic storage device as claimed in claim 6 wherein said bits of information are stored encoded in said topology of said domain wall of said magnetic bubble using at least one of a three-ring state and a single domain. ### Claim 8 (depends on 6) A magnetic storage device as claimed in claim 6 further comprising a mechanism to apply a magnetic field gradient pulse or an electrical current excitation to said magnetic bubble to change a value of a said stored bit. ### Claim 9 (depends on 1) A method as claimed in claim 1, wherein a said magnetic bubble has a maximum dimension of less than 1 μm. ### Claim 10 (depends on 1) A method of reading a bit of information, in particular stored using the method as claimed in claim 1, the method comprising applying a magnetic field or an electrical current excitation to induce different dynamic responses from said topology of said domain wall, and detecting a said dynamic response to identify a said topology of said domain wall of a said magnetic bubble and hence deduce a value of a stored said bit of information. ### Claim 11 (depends on 10) A method of reading a bit of information as claimed in claim 10 wherein said detecting a said dynamic response is by means of magnetoresistive measurement. ### Claim 12 (depends on 10) A method of reading a bit of information as claimed in claim 10 wherein said applying of said magnetic field comprises applying a magnetic field to cause rotation of a topological defect in said domain wall, and wherein said detecting of said dynamic response comprises detecting said rotation. ### Claim 13 (depends on 10) A method of reading a bit of information as claimed in claim 10 wherein said applying of said magnetic field comprises applying a field to change a size of a said magnetic bubble. ### Claim 14 (depends on 10) A method of reading a bit of information as claimed in claim 10, wherein said applying of said magnetic field comprises tuning said magnetic field or said electrical current excitation to an eigenfrequency of said S=1 state of said domain wall. ### Claim 15 (depends on 10) A method of reading a bit of information as claimed in claim 10 wherein said applying of said magnetic field comprises applying a field gradient pulse or electrical current excitation such as charge current or spin polarized current. ### Claim 16 (depends on 1) A device for reading a bit of information in particular stored using the method as claimed in claim 1, the device comprising: means for applying a magnetic field or electrical current excitation such as charge current or spin polarized current to induce different dynamic responses from said topology of said domain wall; and means for detecting a said dynamic response to identify a said topology of said domain wall of a said magnetic bubble and hence deduce a value of a stored said bit of information. ### Claim 17 (depends on 6) A device as claimed in claim 6, further comprising a pair of conductors one to either side of a said magnetic bubble or a said island for writing or reading a topological state of a said domain wall of said magnetic bubble. ### Claim 18 (depends on 3) A method as claimed in claim 3, wherein a said island of magnetic material has a maximum dimension of less than 1 μm. ### Claim 19 (depends on 6) A magnetic storage device as claimed in claim 6, wherein said island of magnetic material has a maximum dimension of less than 1 μm. ### Claim 20 (depends on 5) A method as claimed in claim 5, wherein said electrical current excitation comprises an electrical charge current or a spin polarized current. ### Claim 21 (depends on 8) A magnetic device as claimed in claim 8, wherein said electrical current excitation comprises an electrical charge current or a spin polarized current. ### Claim 22 (depends on 10) A method as claimed in claim 10, wherein said electrical current excitation comprises an electrical charge current or a spin polarized current.