Method and system for coding and read out of information in a microscopic cluster comprising coupled functional islands

• US 8,085,578 B2
• Filed: 06/18/2009
• Issued: 12/27/2011
• Est. Priority Date: 03/13/2009
• Status: Active Grant

• Current Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Original Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Inventors: Heyderman, Laura J., Bisig, André, Braun, Hans-Benjamin, Schrefl, Thomas, Jung, Thomas, Mengotti, Elena, Rodríguez, Arantxa Fraile, Nolting, Frithjof
• Primary Examiner(s): MAI, SON LUU
• Application Number:
  US12/487,388
• Publication Number:
  US 20100232251A1
• Time in Patent Office: 922 Days
• Field of Search: 365/151
• US Class Current: 365/151
• CPC Class Codes: G11C 11/14 using thin-film elements
• CPC Class Codes: G11C 11/56 using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: G11C 11/5607 using magnetic storage elements

Abstract

A method and a system for coding and reading out information in a microscopic cluster formed with coupled functional islands includes: generating the cluster by forming a regular microscopic pattern for locating the functional islands; making use of a physical or chemical property of each individual island and making use of the coupling between the functional islands; assigning different information to different energy levels of the cluster; effecting a change of the physical or chemical property of at least one functional island in order to change the energy level of the cluster to the energy level equivalent to the information content to be coded; and reading out the information. These measures allow forming a cluster having distinct energy levels, each being assigned to a distinct information content. These systems pave the way for future devices based on clusters of coupled islands and, armed with the complete knowledge of the energy states, the door is opened for use of these finite multistate clustered structures in future spintronic devices, for example for data storage, memory applications or to perform logic operations.

Claims

1. A method for coding and reading out information in a microscopic cluster formed with coupled functional islands, which comprises the following method steps:

a) generating the cluster by forming a regular microscopic pattern for locating the functional islands;

b) making use of a physical and/or chemical property of each individual island and making use of the coupling between the functional islands in order to define a plurality of energy levels in each cluster and/or among neighboring clusters;

c) assigning different information to different energy levels of the cluster; and

d) effecting a change of the physical and/or chemical property of at least one functional island in order to change the energy level of the cluster to the energy level equivalent to the information content to be coded; and

e) reading out the information.

2. The method according to claim 1, wherein the physical and/or chemical property, static or dynamic, and the corresponding coupling is at least one selected from a group or groups consisting of:

magnetic dipole orientation within the islands with a magnetic dipolar coupling between the islands;

electric dipole orientation within the islands with an electric dipolar coupling between the islands;

the dimensions, elastic response, hardness, magnetization, electric polarization or optical properties of deformable islands, with e.g an elastic material or springs with tunable spring constants providing a mechanical coupling;

island (e.g. molecular) orientation with the coupling via physical or chemical interaction through a linker species, substrate or other medium;

island (e.g. molecular) charge or spin orientation with coupling via exchange interaction, dipolar interaction, spin or charge transfer;

chemical binding status with coupling via linker molecules, substrate or other medium;

light absorption, reflection or polarisation characteristics, with a coupling via e.g. plasmonic, photonic e.g. fluorescence resonance energy transfer, or thermal interactions through the supporting surface or matrix;

electrical, electronic or spintronic properties (e.g. spin, charge, current flow, conductance/resistance, electrical potential/voltage, capacitance, induction, memristance, current/voltage characteristics) in a device (e.g. active, passive, oxide, molecular device) with coupling via electrical or electronic means (e.g. electric fields, electrostatic fields, current through an interconnect, electric charge transfer, orbital or quantum coupling);

resonant frequency of engineered resonators and oscillators coupled by various means e.g. electromagnetic fields;

resonant frequency of a microscopic system containing islands (e.g. precessing spins, magnetic moments or vibrating molecules), coupled by various means (e.g. electromagnetic fields).

3. The method according to claim 1, wherein the coupling can be modified by the properties of the medium such as electrical properties (e.g. permittivity), magnetic properties (e.g. permeability), mechanical properties (e.g. stiffness), fluid properties (e.g. viscosity), electronic properties (e.g. conductance) or optical properties (e.g. optical conductance), or thermal properties (e.g. heat conductance).

4. The method according to claim 1, wherein each functional island engages in one of at least two possible states with respect to the physical or chemical property.

5. The method according to claim 1, wherein the cluster has a regular form selected from a triangular form and a rectangular form, or any derivative or combination of the regular forms, and each vertex or interconnect of the respective forms can be represented by a functional island.

6. The method according to claim 5, wherein the different energy levels are determined by the number and/or the location of the different couplings of juxtaposed functional islands, for example for vector properties of the islands such as magnetic dipoles, this would be head-to-tail coupling of juxtaposed functional islands and/or the number and/or the location of the head-to-head or tail-to-tail coupling of juxtaposed functional islands.

7. The method according to claim 5, wherein the change of the energy level is effected by at least one of:

a) island-related or cluster-related application of magnetic field;

b) island-related or cluster-related application of electric field;

c) island-related or cluster-related application of electromagnetic field;

d) island-related or cluster-related application of electric current;

e) island-related or cluster-related application of pressure or stress or strain;

f) island-related or cluster-related application of heat or light; and

g) island-related or cluster-related application of electromagnetic radiation or chemically reactive agents.

8. A microscopic system for coding and reading out information in a microscopic cluster formed of coupled functional islands, comprising:

a) at least one cluster being formed as a regular microscopic pattern for locating the functional islands, wherein different information is assigned to different energy levels of at least one cluster and/or neighboring clusters in order to define a plurality of energy levels in each cluster and/or among neighboring clusters;

b) each individual functional island having a physical and/or chemical property and the functional islands are coupled;

c) a means for effecting a change of the physical and/or chemical property of at least one functional island in order to change the energy level of the cluster to the energy level equivalent to the information content to be coded;

d) a means for read out of the information.

9. The system according to claim 8, wherein the physical and/or chemical property, static or dynamical, and the corresponding coupling is at least one selected from a group or groups containing:

magnetic dipole orientation within the islands with a magnetic dipolar coupling between the islands;

electric dipole orientation within the islands with an electric dipolar coupling between the islands;

the dimensions, elastic response, hardness, magnetization, electric polarization or optical properties of deformable islands, with e.g an elastic material or springs with tunable spring constants providing a mechanical coupling;

island (e.g. molecular) orientation with the coupling via physical or chemical interaction through a linker species, substrate or other medium;

island (e.g. molecular) charge or spin orientation with coupling via exchange interaction, dipolar interaction, spin or charge transfer;

chemical binding status with coupling via linker molecules, substrate or other medium;

light absorption, reflection or polarisation characteristics, with a coupling via e.g. plasmonic, photonic e.g. fluorescence resonance energy transfer, or thermal interactions through the supporting surface or matrix;

electrical, electronic or spintronic properties (e.g. spin, charge, current flow, conductance/resistance, electrical potential/voltage, capacitance, induction, memristance, current/voltage characteristics) in a device (e.g. active, passive, oxide, molecular device) with coupling via electrical or electronic means (e.g. electric fields, electrostatic fields, current through an interconnect, electric charge transfer, orbital or quantum coupling);

resonant frequency of engineered resonators and oscillators coupled by various means e.g. electromagnetic fields; and

resonant frequency of a microscopic system containing islands (e.g. precessing spins, magnetic moments or vibrating molecules), coupled by various means (e.g. electromagnetic fields).

10. The system according to claim 8, wherein each functional island engages in one of at least two possible states with respect to the physical or chemical property.

11. The system according to claim 8, wherein the cluster has a regular form selected from a triangular form and a rectangular form, or any derivative or combination of the regular forms, and each vertex or interconnect of the respective forms can be represented by a functional island.

12. The system according to claim 11, wherein the different energy levels are determined by the number and/or the location of the coupling of juxtaposed functional islands and/or the number and/or the location of the coupling of juxtaposed functional islands, for example for vector properties of the islands such as magnetic dipoles, the head-to-tail coupling of juxtaposed functional islands and/or the number and/or the location of the head-to-head or tail-to-tail coupling of juxtaposed functional islands.

13. The system according to claim 11, wherein the change of the energy level is effected by at least one of:

a) island-related or cluster-related application of magnetic field;

b) island-related or cluster-related application of electric field;

c) island-related or cluster-related application of electromagnetic field;

d) island-related or cluster-related application of electric current;

e) island-related or cluster-related application of pressure, stress or strain;

f) island-related or cluster-related application of heat or light; and

g) island-related or cluster-related application of electromagnetic radiation or chemically reactive agents.

14. The system according to claim 11, wherein the energy level is detected by at least one of:

a) island-related or cluster-related measurement with a magnetic field;

b) island-related or cluster-related measurement with an electric field;

c) island-related or cluster-related measurement with an electromagnetic field;

d) island-related or cluster-related measurement with electric current;

e) island-related or cluster-related measurement of pressure stress, or strain;

f) island-related or cluster-related measurement of property associated with heat or light; and

g) island-related or cluster-related measurement of electromagnetic radiation or with chemically reactive agents.

15. The system according to claim 9, wherein the means for reading out comprises an information accessing device, which includes leads such as electrical contacts e.g. in the form of current lines, fiber optic waveguides, contact and non-contact methods using a local probe or recording head, for example either an isolated probe or an array of probes, including optical methods such as focused, near field and uniform illumination.