Magnetic skyrmion writing device and method of forming the same

Abstract

The application relates to a magnetic skyrmion writing device and a forming method thereof, which comprises a magnetic film, a writing unit for writing a magnetic skyrmion to the magnetic film, and a stress providing device for providing a compressive stress or a tensile stress to the magnetic film. According to the positive or negative magnetostriction coefficient of the magnetic film, a magnetization easy axis along the tensile direction or perpendicular to the tensile direction can be generated in the film, and then the energy threshold of the nucleation of the magnetic skyrmion in the film is reduced.

Description

Technical Field

[0001] This invention relates to magnetic skyrmion track memory, and more particularly to a magnetic skyrmion writing device and a method for forming the same. Background Technology

[0002] Magnetic skyrmions are a novel type of spintronic material whose internal magnetic moments rotate continuously, filling the entire space-time matrix. Therefore, they possess a topological number of 1 / -1, exhibiting a topological magnetic structure and soliton properties, retaining their magnetic structure during motion. Magnetic skyrmions can be considered as basic units for storing information; their presence or absence can be represented as "1" and "0" respectively. Magnetic skyrmions can be driven by electric current. Compared to the current-driven domain wall motion in track memory, the critical current driving skyrmions is 5-6 orders of magnitude lower, significantly reducing energy consumption. Therefore, magnetic skyrmions can replace domain walls as storage units to fabricate skyrmion track memory, enabling low-power, high-density magnetic storage media. Besides storing data in an ultra-compact medium, skyrmions can also be combined with storage processing capabilities to make computers run faster and reduce hard drive size, while possessing the computing power of desktop computers.

[0003] The usual method for generating magnetic skyrmions is to use spin-polarized current, but higher current density means that more energy is required, and the heat generated also has a certain impact on the stability of the device. Summary of the Invention

[0004] Therefore, it is necessary to provide a magnetic skyrmion writing device and its formation method that can reduce the energy threshold for the nucleation of magnetic skyrmions in magnetic thin films.

[0005] To achieve the above objectives, the present invention provides a magnetic skyrmion writing device, comprising:

[0006] Magnetic thin film;

[0007] A writing unit is used to write magnetic skyrmions into the magnetic thin film;

[0008] A stress-providing device for providing compressive or tensile stress to the magnetic thin film.

[0009] In one embodiment, the stress-providing device includes a rigid structure comprising an arc surface, and the magnetic thin film is disposed on the arc surface to bend with the arc surface.

[0010] In one embodiment, the magnetic skyrmion writing device further includes a flexible substrate disposed between the magnetic thin film and the rigid structure, wherein the flexible substrate and the magnetic thin film bend with the curved surface.

[0011] In one embodiment, a magnetically conductive portion is further formed on the rigid structure, the material of the magnetically conductive portion is a magnetically conductive material, and the material of the rigid structure is a non-magnetically conductive material; the magnetic thin film is disposed in the region on the rigid structure where the magnetically conductive portion is formed.

[0012] In one embodiment, the rigid structure has a through hole, and the magnetic conductive part is located on the side of the rigid structure opposite to the arc surface and extends into the through hole.

[0013] In one embodiment, the area where the writing unit writes magnetic skyrmions to the magnetic thin film is the area where the magnetic thin film region is aligned with the via.

[0014] On the other hand, the present invention also provides a method for forming a magnetic skyrmion writing device, comprising:

[0015] Obtain a rigid structure, wherein the rigid structure includes an arc surface;

[0016] A magnetic thin film is attached to the curved surface, thereby causing the magnetic thin film to bend with the curved surface; the magnetic thin film is used to write magnetic skyrmions into the magnetic thin film through a writing unit.

[0017] In one embodiment, before the step of attaching the magnetic film to the arc surface, the step further includes forming the magnetic film on a first surface of the flexible substrate. The step of attaching the magnetic film to the arc surface involves attaching the flexible substrate to the arc surface. The side of the flexible substrate that contacts the arc surface is the second side of the flexible substrate, and the second side is opposite to the first side.

[0018] In one embodiment, the flexible substrate is made of polyethylene naphthalate or polyethylene terephthalate (1,4-cyclohexanediol).

[0019] In one embodiment, during the step of obtaining the rigid structure, a magnetically conductive portion is further formed on the obtained rigid structure, wherein the material of the magnetically conductive portion is a magnetically conductive material, and the material of the rigid structure is a non-magnetically conductive material;

[0020] In the step of attaching the magnetic film to the curved surface, the magnetic film is attached to the area on the rigid structure where a magnetic conductive part is formed.

[0021] The aforementioned magnetic skyrmion writing device and its formation method introduce tensile or compressive stress into the magnetic thin film through a stress providing device, thereby reducing the energy threshold for the nucleation of magnetic skyrmions in the magnetic thin film. Therefore, using a magnetic skyrmion writing device can effectively reduce the energy consumption for writing skyrmions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a top view schematic diagram of a magnetic thin film grown on a flexible substrate in one embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the tensile stress providing device in one embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of a magnetic thin film attached to the arc surface of a tensile stress providing device in one embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the compressive stress providing device in one embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of a magnetic thin film attached to the arc surface of a compressive stress providing device in one embodiment of the present invention;

[0028] Figure 6 This invention provides a flowchart of a method for forming a magnetic skyrmion writing device. Detailed Implementation

[0029] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0032] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0033] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0034] Magnetic skyrmions are a novel type of spintronic material whose internal magnetic moments rotate continuously, filling the entire space-time matrix. Therefore, they possess a topological number of 1 / -1, exhibiting a topological magnetic structure and soliton properties, retaining their magnetic structure during motion. Magnetic skyrmions can be considered as basic units for storing information; their presence or absence can be represented as "1" and "0" respectively. Magnetic skyrmions can be driven by electric current. Compared to the current-driven domain wall motion in track memory, the critical current for driving skyrmions is 5-6 orders of magnitude lower, significantly reducing energy consumption. Therefore, magnetic skyrmions can replace domain walls as storage units to fabricate skyrmion track memory, enabling low-power, high-density magnetic storage media. While methods for generating magnetic skyrmions typically utilize spin-polarized currents, higher current densities require higher energy consumption, and the resulting heat can negatively impact device stability.

[0035] Magnetic materials exhibit magnetostriction, meaning that changes in their magnetization state lead to changes in their length and volume. Conversely, if a magnetic material is subjected to pressure or tension, causing a change in its length or volume, its internal magnetization state will also change accordingly; this effect is called piezomagnetism. Therefore, we can change the internal magnetization state of a magnetic thin film by introducing tensile or compressive stress.

[0036] Accordingly, this application provides a magnetic skyrmion writing device, comprising:

[0037] Magnetic thin film;

[0038] A writing unit is used to write magnetic skyrmions into the magnetic thin film;

[0039] A stress-providing device for providing compressive or tensile stress to the magnetic thin film.

[0040] By introducing tensile stress into the magnetic thin film, a magnetization easy axis along or perpendicular to the tensile direction is generated in the magnetic thin film, depending on whether the magnetostriction coefficient of the magnetic material is positive or negative, thereby reducing the energy threshold for the nucleation of magnetic skyrmions in the magnetic thin film. Similarly, by introducing compressive stress into the magnetic thin film, a magnetization easy axis perpendicular to or along the compressive stress direction is generated in the magnetic thin film, depending on whether the magnetostriction coefficient of the magnetic material is positive or negative, thereby reducing the energy threshold for the nucleation of magnetic skyrmions in the magnetic thin film. Therefore, the aforementioned magnetic skyrmion writing device, by introducing tensile or compressive stress into the magnetic thin film through a stress-providing device, can reduce the energy threshold for the nucleation of magnetic skyrmions in the magnetic thin film, thus effectively reducing the energy consumption for writing skyrmions.

[0041] In one embodiment, the magnetic skyrmion writing device further includes a flexible substrate disposed between the magnetic thin film and the rigid structure, wherein the flexible substrate and the magnetic thin film bend with the curved surface.

[0042] Figure 1 This is a top view schematic diagram of a magnetic thin film grown on a flexible substrate in one embodiment of the present invention.

[0043] A magnetic thin film 102, which generates magnetic skyrmions, is grown on a flexible substrate 101. Stress can be introduced into the magnetic thin film 102 by straining the flexible substrate 101. In one embodiment, the flexible substrate is made of polyethylene naphthalate or polyethylene terephthalate (1,4-cyclohexanediol). By placing the magnetic thin film 102 on the flexible substrate 101, it can be transferred using the flexible substrate 101. That is, when it is necessary to change the position or environment of the magnetic thin film 102, it can be moved by moving the flexible substrate 101.

[0044] Figure 2 A tensile stress providing device is provided for providing tensile stress to a magnetic thin film 102. For example... Figure 2 As shown, the tensile stress providing device includes a rigid structure 200, which includes an arc surface 201. A magnetically conductive portion 203 is also formed on the rigid structure 200. In one embodiment, the magnetically conductive portion 203 is made of a magnetically conductive material, such as permalloy, but other highly magnetically conductive materials can also be used; no further limitation is made here. The rigid structure 200 is made of a non-magnetically conductive material, such as stainless steel, but other non-magnetically conductive materials can also be used.

[0045] The rigid structure 200 has a through hole 202, and the magnetically conductive part 203 is disposed on the side of the rigid structure 200 opposite to the arc surface 201 and extends into the through hole. In one embodiment, the top end of the magnetically conductive part 203 has the same curvature as the arc surface 201.

[0046] Figure 3 This is a schematic diagram of the structure of a magnetic thin film attached to the arc surface of the aforementioned tensile stress providing device in one embodiment of the present invention. The magnetic thin film 102 is disposed on the arc surface 201 in a region where a magnetically conductive portion is formed, thereby bending with the arc surface so that the top surface of the magnetic thin film 102 has the same curvature as the arc surface 201. In one embodiment, the magnetic skyrmion writing device further includes a flexible substrate 101, which is disposed between the magnetic thin film 102 and the rigid structure 200, and both the flexible substrate 101 and the magnetic thin film 102 bend with the arc surface 201. In other embodiments, the stress applied to the magnetic thin film 102 is achieved by stress providing devices with different curvatures.

[0047] The magnetic conductive part 203 is disposed on the side of the rigid structure 200 opposite to the arc surface 201 and extends into the through hole 202. Figure 3 (Not indicated), in contact with the flexible substrate 101.

[0048] The area where the writing unit writes magnetic skyrmions into the magnetic thin film is the area where the magnetic thin film aligns with the through-hole. A magnetic field is applied to the magnetically conductive portion 203 to achieve the purpose of writing magnetic skyrmions into the magnetic thin film. In one embodiment, the material of the magnetically conductive portion 203 is a magnetically conductive material, such as permalloy; however, other highly magnetically conductive materials can also be used, and no further limitation is made here. The material of the rigid structure 200 is a non-magnetically conductive material, such as stainless steel; other non-magnetically conductive materials can also be used. Compared to a solution where the entire rigid structure 200 is made of a magnetically conductive material, using a small-area magnetically conductive portion 203 to introduce the magnetic field to the surface of the magnetic thin film 102 can achieve a more uniform magnetic field introduction.

[0049] By attaching the magnetic thin film 102 and the flexible substrate 101 to the arc surface 201 of the rigid structure 200, the flexible substrate 101 is deformed, thereby introducing tensile stress into the magnetic thin film 102. Depending on whether the magnetostriction coefficient of the magnetic material is positive or negative, a magnetization easy axis will be generated in the magnetic thin film 102 along the tension direction or perpendicular to the tension direction, thereby reducing the energy threshold for the nucleation of magnetic skyrmions in the magnetic thin film 102.

[0050] The present invention also provides a compressive stress providing device, such as Figure 4As shown, this device provides compressive stress to the magnetic thin film. The compressive stress providing device includes a rigid structure 300, which includes an arc surface 301. A magnetically conductive portion 303 is also formed on the rigid structure 300. In one embodiment, the magnetically conductive portion 303 is made of a magnetically conductive material, such as permalloy, but other highly magnetically conductive materials can also be used; no further limitation is made here. The rigid structure 300 is made of a non-magnetically conductive material, such as stainless steel, but other non-magnetically conductive materials can also be used.

[0051] The rigid structure 300 has a through hole 302, and the magnetically conductive part 303 is disposed on the side of the rigid structure 300 opposite to the arc surface 301 and extends into the through hole 302. In one embodiment, the top end of the magnetically conductive part 303 has the same curvature as the arc surface 301.

[0052] Figure 5 This is a schematic diagram of the structure of a magnetic thin film attached to the arc surface of the aforementioned compressive stress providing device in one embodiment of the present invention. The magnetic thin film 102 is disposed on the region where a magnetically conductive portion is formed on the arc surface 201, thereby bending with the arc surface so that the top surface of the magnetic thin film 102 has the same curvature as the arc surface 201. In one embodiment, the magnetic skyrmion writing device further includes a flexible substrate 101, which is disposed between the magnetic thin film 102 and the rigid structure 300, and the flexible substrate 101 and the magnetic thin film 102 bend with the arc surface 301. In other embodiments, the stress applied to the magnetic thin film 102 can be achieved by stress providing devices with different curvatures.

[0053] The magnetic conductive part 303 is disposed on the side of the rigid structure 300 opposite to the arc surface 301 and extends into the through hole 302. Figure 5 (Not indicated), in contact with the flexible substrate 101.

[0054] The area where the writing unit writes magnetic skyrmions into the magnetic thin film is the area where the magnetic thin film aligns with the through-hole. A magnetic field is applied to the magnetically conductive portion 303 to achieve the purpose of writing magnetic skyrmions into the magnetic thin film. In one embodiment, the material of the magnetically conductive portion 303 is a magnetically conductive material, such as permalloy; however, other highly magnetically conductive materials can also be used, and no further limitation is made here. The material of the rigid structure 300 is a non-magnetically conductive material, such as stainless steel; other non-magnetically conductive materials can also be used. Compared to a solution where the entire rigid structure 300 is made of a magnetically conductive material, using a small-area magnetically conductive portion 303 to introduce the magnetic field to the surface of the magnetic thin film 102 can achieve a more uniform magnetic field introduction.

[0055] By attaching the magnetic thin film 102 and the flexible substrate 101 to the arc surface 301 of the rigid structure 300, the flexible substrate 101 is deformed, thereby introducing compressive stress into the magnetic thin film 102. Depending on whether the magnetostriction coefficient of the magnetic material is positive or negative, a magnetization easy axis will be generated in the magnetic thin film 102 along the tension direction or perpendicular to the tension direction, thereby reducing the energy threshold for the nucleation of magnetic skyrmions in the film.

[0056] Furthermore, the present invention also provides a method for forming a magnetic skyrmion writing device, such as... Figure 6 .

[0057] The method is as follows:

[0058] Step 601: Obtain a rigid structure, wherein the rigid structure includes an arc surface.

[0059] In one embodiment, a magnetically conductive portion is also formed on the obtained rigid structure, wherein the material of the magnetically conductive portion is a magnetically conductive material, and the material of the rigid structure is a non-magnetically conductive material.

[0060] Step 602: Attach the magnetic film to the curved surface so that the magnetic film bends with the curved surface.

[0061] The magnetic thin film obtained by the above method has a low energy threshold for the nucleation of magnetic skyrmions, thus resulting in low energy consumption when writing magnetic skyrmions into the magnetic thin film using a writing unit. In one embodiment, a step of forming the magnetic thin film on a first surface of a flexible substrate is included before step 602. Accordingly, by attaching the flexible substrate to the curved surface, the magnetic thin film and the flexible substrate are bent along the curved surface of the rigid structure. The side of the flexible substrate in contact with the curved surface is the second side of the flexible substrate, which is opposite to the first side.

[0062] In one embodiment, the magnetic thin film is the area on the rigid structure where a magnetically conductive portion is formed.

[0063] The above-described method for forming a magnetic skyrmion writing device involves deforming the flexible substrate, thereby introducing compressive or tensile stress into the magnetic thin film. Depending on whether the magnetostriction coefficient of the magnetic material is positive or negative, a magnetization easy axis will be generated in the thin film along or perpendicular to the tension direction, thereby reducing the nucleation energy threshold of magnetic skyrmions in the thin film.

[0064] In one embodiment, the flexible substrate is made of polyethylene naphthalate or polyethylene terephthalate (1,4-cyclohexanediol).

[0065] In one embodiment, the rigid structure has a through-hole, and the magnetically conductive portion is located on the side of the rigid structure opposite to the curved surface and extends into the through-hole. In one embodiment, the magnetic thin film region aligned with the through-hole is the region where magnetic skyrmions are written.

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A magnetic skyrmion writing device, characterized by, The application relates to a magnetic skyrmion writing device, comprising: a magnetic thin film and a flexible substrate, wherein the magnetic thin film is grown on the flexible substrate; a hard structure, which comprises a curved surface, a magnetic conductive part and a through hole, the magnetic conductive part is arranged on the side of the hard structure opposite to the curved surface and extends into the through hole, and the magnetic thin film is arranged on the curved surface and bends along with the curved surface; a writing unit, which is used for writing magnetic skyrmions into the magnetic thin film, and the region of the magnetic thin film, which is written into by the writing unit, is the region of the magnetic thin film, which is aligned with the through hole; a stress providing device, which is used for providing compressive stress or tensile stress for the magnetic thin film.

2. The magnetic skyrmion writing device of claim 1, wherein, The material of the flexible substrate is polyethylene naphthalate or poly-1,4-cyclohexane dimethylene terephthalate.

3. The magnetic skyrmion writing device of claim 1, wherein, The flexible substrate is arranged between the magnetic thin film and the hard structure, and the flexible substrate and the magnetic thin film bend along with the curved surface.

4. The magnetic skyrmion writing device of claim 1, wherein, The material of the magnetic conductive part is a magnetic conductive material, and the material of the hard structure is a non-magnetic conductive material; the magnetic thin film is arranged on the region of the hard structure, which is provided with the magnetic conductive part.

5. The magnetic skyrmion writing device of claim 1, wherein, The top end of the magnetic conductive part has the same curvature as the curved surface.

6. The magnetic skyrmion writing device of claim 1, wherein, The magnetic thin film and the flexible substrate are attached to the curved surface of the hard structure, so that the flexible substrate is deformed.

7. A method for forming a magnetic skyrmion writing device, comprising: obtaining a hard structure, which comprises a curved surface, a magnetic conductive part and a through hole, the magnetic conductive part is arranged on the side of the hard structure opposite to the curved surface and extends into the through hole, and a magnetic thin film is arranged on the curved surface and bends along with the curved surface; attaching the magnetic thin film to the curved surface so that the magnetic thin film bends along with the curved surface; the magnetic thin film is used for writing magnetic skyrmions into the magnetic thin film by a writing unit, the region of the magnetic thin film, which is written into by the writing unit, is the region of the magnetic thin film, which is aligned with the through hole, and the magnetic thin film is grown on a flexible substrate.

8. The method of forming a magnetic skyrmion writing device of claim 7, wherein, Before the step of attaching the magnetic thin film to the curved surface, the method further comprises the step of forming the magnetic thin film on the first surface of the flexible substrate, and the step of attaching the magnetic thin film to the curved surface is to attach the flexible substrate to the curved surface, the surface of the flexible substrate, which is in contact with the curved surface, is the second surface of the flexible substrate, and the second surface is opposite to the first surface.

9. The method of forming a magnetic skyrmion writing device of claim 8, wherein, The material of the flexible substrate is polyethylene naphthalate or poly-1,4-cyclohexane dimethylene terephthalate.

10. The method of forming a magnetic skyrmion writing device of claim 7, wherein, In the step of obtaining the hard structure, the material of the magnetic conductive part is a magnetic conductive material, and the material of the hard structure is a non-magnetic conductive material; In the step of attaching the magnetic thin film to the curved surface, the magnetic thin film is attached to the region of the hard structure, which is provided with the magnetic conductive part.

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