Patent Application
20220375504
The present disclosure relates to the field of magnon lasers employed to generate terahertz radiation.
Data centers represent the information backbone of an increasingly digitalized world. Demand for their services has been rising rapidly, and data-intensive technologies such as artificial intelligence, smart and connected energy systems, distributed manufacturing systems, and autonomous vehicles promise to increase demand further. Given that data centers are energy-intensive enterprises, estimated to account for around 1% of worldwide electricity use, these trends have clear implications for global energy demand and must be analyzed rigorously. Several often cited yet simplistic analyses claim that the energy used by the world's data centers has doubled over the past decade and that their energy use will triple or even quadruple within the next decade.
The data centers are becoming the biggest consumers of electricity world-wide. Indeed, data centers are among the highest consumers of electric power. Studies have shown that data center energy consumption continues to increase annually, with two identifiable trends.
The first trend is that mainstream legacy corporate data centers continue to be major consumers of power, despite many organizations migrating systems and hardware to cloud environments. But, while average use is increasing steadily, it's doing so at a lower rate than perhaps 20 years ago when cloud data centers were emerging as a major alternative to legacy facilities.
The other trend is that, while large cloud data centers, often called hyperscale centers, are steadily increasing their power usage, they're balancing that increase by investing in green initiatives, such as energy-efficient equipment. They're also revamping supporting systems such as HVAC, security and lighting.
The pecking order (a hierarchy of status) of memory and storage device is a critical component of various computer systems. Processor caches act as a subset of data and instructions stored in the memory. Data stored in the main memory are stored in large, slow storage devices, such as disks and flash. Data from modern applications such books, maps, photos, audios, videos, references, facts, and conversations rely on both real and offline processing and their dataset can be in gigabytes, terabytes, zettabytes or even larger in size.
Regrettably, the scaling of conventional memory technologies is at risk. Memory technologies, such as SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory), are experiencing scalability challenges as a result to the limitations of their device cell size and power dissipation.
Indeed, all current methods of writing and reading the data involve usage of an injected electrical current. This injected current after performing its memory function has to be dissipated into the recording medium.
The present application discloses an apparatus and method for terahertz-based reading of data recorded in RKKY-based magnetic memory with negligible dissipation of energy in the medium because both the reading and writing operations are performed without sending electric current via the magnetic cell itself.
The Figures can have the same, or similar, reference signifiers in the form of labels (such as alphanumeric symbols, e.g., reference numerals), and can signify aa similar or equivalent function or use. Further, reference signifiers of the same type can be distinguished by appending to the reference label a dash and a second label that distinguishes among the similar signifiers. If only the first label is used in the Specification, its use applies to any similar component having the same label irrespective of any other reference labels. A brief list of the Figures is below.
In the Figures, reference signs can be omitted as is consistent with accepted engineering practice; however, a skilled person will understand that the illustrated components are understood in the context of the Figures as a whole, of the accompanying writings about such Figures, and of the embodiments of the claimed inventions.
The Figures and Detailed Description, only to provide knowledge and understanding, signify at/at least one ECIN. To minimize the length of the Detailed Description, while various features, structures or characteristics can be described together in a single embodiment, they also can be used in other embodiments without being written about. Variations of any of these elements, and modules, processes, machines, systems, manufactures, or compositions disclosed by such embodiments and/or examples are easily used in commerce. The Figures and Detailed Description signify, implicitly or explicitly, advantages and improvements of at least one ECIN for use in commerce.
In the Figures and Detailed Description, numerous specific details can be described to enable at least one ECIN. Any embodiment disclosed herein signifies a tangible form of a claimed invention. To not diminish the significance of the embodiments and/or examples in this Detailed Description, some elements that are known to a skilled person can be combined for presentation and for illustration purposes and not be specified in detail. To not diminish the significance of these embodiments and/or examples, some well-known processes, machines, systems, manufactures, or compositions are not written about in detail. However, a skilled person can use these embodiments and/or examples in commerce without these specific details or their equivalents. Thus, the Detailed Description focuses on enabling the inventive elements of any ECIN. Where this Detailed Description refers to some elements in the singular tense, more than one element can be depicted in the Figures and like elements are labeled with like numerals.
A Spin Valve Comprising Two Magnetic Metals Separated by RKKY Spacer (Normal Metal).
If J1,2 between two Ni80Co20 layers, as shown in
If, on the other hand, J1,2 between two Ni80Co20 layers, as shown in
Manipulating the Effective Thickness of RKKY Layer by Terahertz Radiation.
The RKKY-based memory can be achieved only if it is possible to effectively manipulate the thickness of the RKKY layer of the spin valve without changing its physical thickness. Theis can be done by using terahertz radiation. For the reference, please see “Control of the Oscillatory Interlayer Exchange Interaction with Terahertz Radiation”, Uta Meyer e al., PRL 118, 097701 (2017) PHYSICAL REVIEW LETTERS week ending 3 Mar. 2017.
The physics of this effect is based on the idea that RKKY interaction can also be viewed as a scattering problem: the equilibrium spin current J flowing through the spacer N is simply related to the RKKY interaction: The characteristic time scale of the system is the time-of-flight τ through the normal spacer N whose thickness is LN: LN=vF τ; vF is Fermi velocity.
As shown in
In an embodiment of the present technology,
In an embodiment of the present technology, by increasing the amplitude of the bias voltage at some at 10 THz from 250 mV to 750 mV (as shown in
A New Type of Magnetic Memory Based on Tunable Ruderman-Kittel-Kasuya-Yosida (RKKY) Interaction
Thus, the spin valve comprising two magnetic metals separated by RKKY spacer (normal metal) of
Indeed, the effective thickness of the RKKY layer can be changed by applying external terahertz radiation.
Therefore, we have a new type of magnetic memory based on tunable Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction (RKKY-based memory cell) comprising: a first layer of magnetic metal; an RKKY spacer coupled to the first layer of magnetic metal; and a second layer of magnetic layer coupled to the RKKY spacer.
The effective thickness of the RKKY spacer is changed by applied terahertz radiation resulting in changing the sign of RKKY interaction from ferromagnetic to antiferromagnetic, or vice versa, thus enabling an RKKY-tunable magnetic memory cell.
In an embodiment of the present technology, the first state of such RKKY-based memory corresponds to the first sign of RKKY interaction, and wherein the second state of such RKKY-based memory corresponds to the second sign of RKKY interaction.
In an embodiment of the present technology, the first sign of RKKY interaction is selected from the group consisting of: a ferromagnetic sign of RKKY interaction; and an antiferromagnetic sign of RKKY interaction.
In an embodiment of the present technology, the second sign of RKKY interaction is selected from the group consisting of a ferromagnetic sign of RKKY interaction; and an antiferromagnetic sign of RKKY interaction.
In operation, a method for changing the sign of a Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in a RKKY-based memory cell comprises the following steps applying terahertz radiation to the RKKY-based memory cell by using Terahertz Magnon Laser; and changing a bias voltage applied to the Terahertz Magnon Laser.
The change of the bias voltage results in changing the sign of RKKY interaction from a first sign of RKKY interaction to a second sign of RKKY interaction; thus, enabling an RKKY-based magnetic memory cell; wherein the first state of such memory corresponds to the first sign of RKKY interaction, and wherein the second state of such memory corresponds to the second sign of RKKY interaction.
In an embodiment of the present technology, a method for changing the sign of a Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in a RKKY-based memory cell comprises the following steps: applying terahertz radiation to the RKKY-based memory cell by using Terahertz Magnon Laser; and changing amplitude of the generated terahertz radiation.
In an embodiment of the present technology, a method for changing the sign of a Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in a RKKY-based memory cell comprises the following steps: applying terahertz radiation to the RKKY-based memory cell by using Terahertz Magnon Laser; and tuning frequency of the generated terahertz radiation.
In an embodiment of the present technology; the amplitude of the generated terahertz radiation is changed by increasing the bias voltage near a first transition point (on
In an embodiment of the present technology; the amplitude of the generated terahertz radiation is changed by increasing the bias voltage near a second transition point (on
In an embodiment of the present technology; by applying a modulating voltage near the first transition point one can enable modulation of the RKKY interaction thus enabling recording the data encoded into the modulating voltage into the RKKY-based memory cell.
In an embodiment of the present technology; by applying a modulating voltage near the second transition point one can enable modulation of the RKKY interaction thus enabling recording the data encoded into the modulating voltage into the RKKY-based memory cell.
The above discussion has set forth the operation of various exemplary systems and devices, as well as various embodiments pertaining to exemplary methods of operating such systems and devices. In various embodiments, one or more steps of a method of implementation (calculating the optimum voltage bias, for example) are carried out by a processor under the control of computer-readable and computer-executable instructions. Thus, in some embodiments, these methods are implemented via a computer.
In an embodiment, the computer-readable and computer-executable instructions may reside on computer useable/readable media.
Therefore, one or more operations of various embodiments may be controlled or implemented using computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. In addition, the present technology may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer-storage media including memory-storage devices.
Although specific steps of exemplary methods of implementation are disclosed herein, these steps are examples of steps that may be performed in accordance with various exemplary embodiments. That is, embodiments disclosed herein are well suited to performing various other steps or variations of the steps recited. Moreover, the steps disclosed herein may be performed in an order different than presented, and not all of the steps are necessarily performed in a particular embodiment.
Although various electronic and software-based systems are discussed herein, these systems are merely examples of environments that might be utilized and are not intended to suggest any limitation as to the scope of use or functionality of the present technology. Neither should such systems be interpreted as having any dependency or relation to any one or combination of components or functions illustrated in the disclosed examples.
Although the subject matter has been described in a language specific to structural features and/or methodological acts, the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as exemplary forms of implementing the claims.
This application is a continuation-in-part of, and claims priority of the application Ser. No. 17/853,059, filed on Jun. 29, 2022, and titled “Apparatus and Method for terahertz-based reading of data recorded into RKKY (Ruderman-Kittel-Kasya-Yosida)-based magnetic memory without dissipation of energy in the medium”. This application is a continuation-in-part of, and claims priority of the application Ser. No. 17/002,431 filed on Aug. 25, 2020, and titled “Novel Technique of High-Speed Magnetic recording based on Manipulating pinning layer in Magnetic Tunnel Junction-based memory by using Terahertz Magnon Laser”. This application is a continuation-in-part of, and claims priority to, U.S. Pat. No. 10,790,635 “Technique of high-speed magnetic recording based on manipulating pinning layer in magnetic tunnel junction-based memory by using Terahertz Magnon Laser”; issued on Sep. 29, 2020. This application is a continuation-in-part of, and claims priority of the U.S. Pat. No. 10,892,602 “Tunable multilayer Terahertz Magnon Generator” issued on Jan. 12, 2021 This application is a continuation-in-part of, and claims priority of the U.S. Pat. No. 10,804,671 “Terahertz Magnon Generator comprising plurality of single Terahertz Magnon Lasers” issued on Oct. 13, 2020. The U.S. Pat. Nos. 10,790,635; 10,804,671 and 10,892,602 are assigned to Magtera, Inc. The entireties of the foregoing patent and patent applications listed herein are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17853059 | Jun 2022 | US |
| Child | 17881440 | US | |
| Parent | 17002431 | Aug 2020 | US |
| Child | 17853059 | US | |
| Parent | 16704090 | Dec 2019 | US |
| Child | 17002431 | US | |
| Parent | 16245224 | Jan 2019 | US |
| Child | 16704090 | US | |
| Parent | 16245247 | Jan 2019 | US |
| Child | 16245224 | US |
