Nanometer oscillator array and preparation method thereof, oscillation network and computing device

Abstract

The embodiment of the invention provides a nano oscillator array based on spin transfer torque, a preparation method of the nano oscillator array, an oscillation network and a computing device. The nano oscillator array comprises a seed crystal layer, a nano column common layer and a nano column array, wherein the nano column common layer and the nano column array are sequentially formed in the direction away from the seed crystal layer; the nano-column sharing layer at least comprises a first magnetic thin film layer; the nano-column array comprises a plurality of nano-columns which are arranged in an array mode, and each nano-column correspondingly generates a nano-spin oscillator; each nanorod comprises a second magnetic thin film layer and a cap layer which are sequentially arranged in the direction far away from the seed crystal layer. According to the invention, shunting of in-plane current can be improved, and the density of effective current and the coupling strength of the nano oscillator are obviously improved.

Description

Technical Field

[0001] The present application relates to the field of oscillator technology, and in particular to a nano-oscillator array and a preparation method, an oscillation network, and a computing device thereof. Background Art

[0002] Nano oscillators are the core components of microwave signal generators. They are widely used in various microwave systems such as communications, radars, electronic countermeasures, and test instruments. Among them, spin-transfer torque nano oscillators (STNOs) are microwave oscillators used to achieve wide-spectrum operating frequencies and high modulation rates in the fields of neuromorphic computing and wireless communications. Due to their wide-spectrum operating frequencies and high modulation rates, they have attracted widespread attention as a new type of nano oscillator. Existing spin-transfer torque nano oscillators usually have a sandwich structure, free layer / intermediate layer / fixed layer, where the free layer and the fixed layer are magnetic layers (ferromagnetic, antiferromagnetic, synthetic ferromagnetic, synthetic antiferromagnetic, etc.), and the intermediate layer is a non-magnetic metal layer or a non-magnetic insulating barrier layer. The current flows into the nano contact area between the electrode and the oscillator, passes through the polarized fixed layer to form polarized spins, enters the free layer, and causes the magnetic moment of the free layer to oscillate through the spin transfer torque.

[0003] In the prior art, for example, the patent application with the patent publication number CN110350284B discloses a double-layer spin-transfer torque nano-oscillator array with a simplified insulating barrier layer, but the adjacent spin-transfer torque nano-oscillators are coupled by dipole action, and the coupling strength is low. The patent application with the patent number CN111564686B discloses a double-layer spin-transfer torque nano-oscillator array with a simplified insulating barrier layer, and the nano-oscillator array has a common fixed layer substrate, but the current is injected on the unified substrate to make the nano-oscillator array coupled synchronously, and the substrate area is large and the effective current density is low. The patent application with the patent publication number CN113097379A discloses a magnetically coupled spin-transfer torque nano-oscillator array, which deposits magnetic insulating materials between adjacent nano-oscillators so that the free layers of adjacent nano-oscillators can be coupled through spin waves, but this method requires that the thickness of the magnetic insulating material is basically consistent with the free layer and aligned with the free layer, which has high requirements for preparation and thin film deposition. The patent with the patent publication number WO2017111688A1 discloses a magnetically coupled spin-transfer torque nano-oscillator array, but it belongs to the traditional nano-contact structure, and there are problems such as current shunting in the cap layer and the free layer, and the reduction of effective current density.

[0004] It should be noted that the above statements are only used to provide background technical information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0005] The embodiments of the present application provide a nano-oscillator array based on spin transfer torque and a preparation method, an oscillation network, and a computing device thereof, which can improve the shunting of in-plane current, significantly increase the density of effective current, and the coupling strength of the nano-oscillator.

[0006] In a first aspect, an embodiment of the present application provides a nano-oscillator array based on spin transfer torque, comprising a seed layer and a nano-column common layer and a nano-column array sequentially formed in a direction away from the seed layer; the nano-column common layer at least comprises a first magnetic film layer;

[0007] The nanocolumn array includes a plurality of nanocolumns arranged in an array, each of the nanocolumns corresponding to a nanospin oscillator; each of the nanocolumns includes a second magnetic film layer and a cap layer sequentially arranged in a direction away from the seed crystal layer.

[0008] In an optional embodiment, the first magnetic film layer includes a synthetic antiferromagnetic layer;

[0009] The second magnetic film layer includes a magnetic reference layer, a nonmagnetic insulating barrier layer, and a magnetic free layer which are sequentially formed in a direction away from the first magnetic film layer.

[0010] In an optional embodiment, the synthetic antiferromagnetic layer includes an antiferromagnetic layer, a magnetic layer and a non-magnetic intermediate layer which are sequentially formed in a direction away from the seed crystal layer.

[0011] In an optional embodiment, the first magnetic film layer includes a magnetic free layer and a non-magnetic insulating barrier layer;

[0012] The second magnetic film layer includes a magnetic reference layer and a synthetic antiferromagnetic layer which are sequentially formed in a direction away from the first magnetic film layer.

[0013] In an optional embodiment, the synthetic antiferromagnetic layer includes a non-magnetic intermediate layer, a magnetic layer and an antiferromagnetic layer which are sequentially formed in a direction away from the seed crystal layer.

[0014] In an optional embodiment, the material of the synthetic antiferromagnetic layer includes any one of iridium-manganese alloy, manganese-platinum alloy and manganese-selenium alloy; the material of the magnetic layer includes one or more of cobalt-iron alloy, cobalt-iron-boron alloy, metal cobalt and nickel-iron alloy; the material of the non-magnetic intermediate layer includes any one of metal ruthenium, metal tungsten and metal copper.

[0015] In an optional embodiment, the material of the magnetic free layer and the material of the magnetic reference layer are any one of ferromagnetism, antiferromagnetism, ferrimagnetism, synthetic antiferromagnetism, synthetic ferrimagnetism and synthetic ferromagnetism.

[0016] In an optional embodiment, the material of the non-magnetic insulating barrier layer includes magnesium oxide or aluminum oxide.

[0017] In an optional embodiment, the material of the capping layer includes one or more of metal tantalum, metal ruthenium and metal platinum.

[0018] In a second aspect, an embodiment of the present application provides a method for preparing a nano oscillator array, which is used to prepare the nano oscillator array described in the first aspect, and the method comprises:

[0019] Depositing a film stack and a hard mask of the nano-oscillator array on a substrate in sequence; the film stack is used to form a seed layer, a nano-column common layer and a nano-column array of the nano-oscillator array;

[0020] forming a first mask pattern on the hard mask, and performing a first etching on the film stack based on the hard mask having the first mask pattern, etching to the upper surface of the seed layer;

[0021] A second mask pattern is formed on the hard mask, and a second etching is performed on the film stack based on the hard mask having the second mask pattern, until the etching reaches the nanorod common layer.

[0022] In a third aspect, an embodiment of the present application provides an oscillation network, comprising a microwave conductor and the nano-oscillator array described in the first aspect; the microwave conductor generates a corresponding magnetic field based on an input microwave signal to be processed, and the magnetic field is coupled to the nano-oscillator array; the nano-oscillator array generates a corresponding oscillation frequency based on different input currents, and the nano-oscillators in the nano-oscillator array whose oscillation frequencies match the frequency of the microwave signal are phase-locked.

[0023] In a fourth aspect, an embodiment of the present application provides a reservoir computing device based on a nano-oscillator array, comprising: an input layer and an output layer, and an oscillator reservoir formed by the nano-oscillator array of the first aspect, wherein the oscillator reservoir is arranged between the input layer and the output layer;

[0024] The input layer is used to inject the pulse signal of the signal to be processed into the oscillator reserve pool; the nano-oscillators in the oscillator reserve pool are coupled to each other, and the pulse signal of the signal to be processed is mapped to a higher-dimensional state space to generate high-dimensional feature data; the output layer is used to linearly output the high-dimensional feature data.

[0025] The technical solution provided in the embodiments of the present application has at least the following technical effects or advantages:

[0026] The nano-oscillator array based on spin transfer torque provided in the embodiment of the present application, by regulating the film stack structure of the nano-oscillator array, accurately controls the cut-off position of the nano-column etching, solves the problems of in-plane current shunting and weak coupling strength in the traditional spin nano-oscillator, so that the performance of the nano-oscillator array of spin transfer torque is improved, and the operation is more reliable and stable. At the same time, the spin transfer torque nano-oscillator array based on magnetic coupling realizes strong coupling between oscillators. The synchronization behavior of each oscillator is realized by spin waves, dipole action and input phase locking, thereby improving the computing power and robustness of the entire computing system based on the nano-oscillator array. And the structure of the spin nano-oscillator array is compatible with the existing CMOS (Complementary Metal-Oxide-Semiconductor, complementary metal oxide semiconductor) integration process, has high controllability and scalability, is conducive to large-scale implementation and preparation, and provides the possibility for realizing the integrated application of high-speed, high-density random computing and neuromorphic computing, and has broad application prospects and commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0028] Figure 1 A schematic structural diagram of a nano-oscillator array based on spin transfer torque provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of a specific structure of a nano-oscillator array based on spin transfer torque provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of the specific structure of another nano-oscillator array based on spin transfer torque provided in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of a process for preparing a nano-oscillator array provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of a specific process of a method for preparing a nano-oscillator array provided in an embodiment of the present application;

[0033] Figure 6 A schematic diagram of the structure of an oscillating network provided in an embodiment of the present application;

[0034] Figure 7A schematic diagram of the structure of a reservoir computing device based on a nano-oscillator array provided in this application. DETAILED DESCRIPTION

[0035] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0036] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by technicians in the field to which this application belongs.

[0037] In the related technology, spin-transfer torque nano-oscillators can be mainly divided into four categories: point contact type, nano-contact type, nano-column type, and hybrid type. Among them, the point contact type directly contacts the oscillator through a metal probe, which has reliability and damage problems. The nano-contact type forms nano-vias on the insulating protective layer through photolithography and etching technology, and evaporates electrodes in the vias to form nano-point contacts. There are problems of in-plane current shunting, reducing the effective current density, and increasing the threshold current. The nano-column type etches the entire oscillator membrane stack into nano-columns through photolithography and etching processes, which minimizes the problem of in-plane current shunting and increases the effective current density. However, the preparation is challenging, and it is difficult to achieve coupling between oscillators between completely isolated nano-columns. The hybrid type combines the nano-contact and nano-column structures, and reduces the threshold current by forming nano-contacts by thinning the cap layer, but it is difficult to eliminate the impact of in-plane current shunting.

[0038] In order to eliminate or reduce the in-plane current shunting and improve the coupling strength of the spin-transfer torque nanooscillator, this embodiment studies the structure of the spin-transfer torque nanooscillator, and finds that by regulating the membrane stack structure of the spin-transfer torque nanooscillator and precisely controlling the cutoff position of nanocolumn etching, the problems of in-plane current shunting and weak coupling strength in traditional spin-transfer torque nanooscillators can be solved.

[0039] Based on the above findings, the present application provides a nano-oscillator array based on spin transfer torque, such as Figure 1As shown, the nano-oscillator may include a seed layer and a nano-column common layer and a nano-column array formed in sequence in a direction away from the seed layer. The nano-column common layer can be understood as a thin film layer shared by the nano-column array, that is, a cut-off layer when etching the nano-columns (cut-off on the upper surface of the layer), or in other words, the layer does not participate in the formation of the nano-columns, and it supports the nano-column array above like the seed layer. The nano-column common layer may include at least a first magnetic film layer, so that more current can flow into the nano-column common layer, so as to reduce the current loss in the surface of the non-magnetic film layer and increase the effective current density. The nano-column array may include a plurality of nano-columns arranged in an array, and each nano-column generates a corresponding nano-spin oscillator; each nano-column may include a second magnetic film layer and a cap layer arranged in sequence in a direction away from the seed layer, and the cap layer may be used to protect the magnetic film layer adjacent thereto.

[0040] The nano-oscillator array based on spin transfer torque provided in this embodiment, by regulating the film stack structure of the nano-oscillator array, accurately controls the cut-off position of the nano-column etching, solves the problems of in-plane current shunting and weak coupling strength in the traditional spin nano-oscillator, so that the performance of the nano-oscillator array of spin transfer torque is improved, and the operation is more reliable and stable. At the same time, the spin transfer torque nano-oscillator array based on magnetic coupling realizes strong coupling between oscillators. The synchronization behavior of each oscillator is realized by means of spin waves, dipole action and input phase locking, thereby improving the computing power and robustness of the entire computing system based on the nano-oscillator array. And the structure of the spin nano-oscillator array is compatible with the existing CMOS (Complementary Metal-Oxide-Semiconductor) integration process, has high controllability and scalability, is conducive to large-scale implementation and preparation, and provides the possibility for realizing the integrated application of high-speed, high-density random computing and neuromorphic computing, and has broad application prospects and commercial value.

[0041] It should be noted that the first magnetic film layer and the second magnetic film layer may include a single film or multiple films. When the first magnetic film layer includes multiple films, a non-magnetic film layer is allowed; when the first magnetic film layer includes a single film, the film is a magnetic film layer, and the nanocolumn common layer is allowed to include other non-magnetic film layers. When the second magnetic film layer includes multiple films, a non-magnetic film layer is allowed; when the second magnetic film layer includes a single film, the film is a magnetic film layer, and the nanocolumn common layer is allowed to include other non-magnetic film layers.

[0042] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0043] Embodiment 1

[0044] Please refer to Figure 2 , is a schematic diagram of the structure of a nano-oscillator array based on spin transfer torque provided by the present application, such as Figure 2 As shown, the nano-oscillator array includes: a seed layer 101 (which can be used as a bottom electrode layer); a synthetic antiferromagnetic layer 102 formed on the seed layer 101; a magnetic reference layer 103 formed on the synthetic antiferromagnetic layer 102; a non-magnetic insulating barrier layer 104 formed on the magnetic reference layer 103; a magnetic free layer 105 formed on the non-magnetic insulating barrier layer 104; and a cap layer 106 formed on the magnetic free layer 105. When etching to form nano-pillars, the etching can be terminated on the synthetic antiferromagnetic layer 102 by an endpoint detection method. One nano-pillar forms one nano-oscillator. The synthetic antiferromagnetic layer 102 is the first magnetic film layer mentioned above; the magnetic reference layer 103, the non-magnetic insulating barrier layer 104 and the magnetic free layer 105 can be collectively referred to as the second magnetic film layer.

[0045] In the spin-transfer torque nano-oscillator array of this embodiment, each nano-pillar forms a nano-spin oscillator, and the nano-spin oscillators share the synthetic antiferromagnetic layer 102. Adjacent nano-spin oscillators are coupled together by dipole action, input phase locking, etc. to form a coupled nano-oscillator array, thereby improving the coupling strength of the nano-oscillator array. When etching to form nano-pillars, the etching can be terminated on the synthetic antiferromagnetic layer by an endpoint detection method, thereby reducing the shunting of the in-plane current in the cap layer 106 and the magnetic free layer 105 to a greater extent, thereby improving the effective current density of the nano-oscillator.

[0046] It should be noted that each nano-oscillator can be configured with an independent input current or a shared input current, and adjacent nano-oscillators can perform current phase locking and gain current output.

[0047] Specifically, the synthetic antiferromagnetic layer 102 may include an antiferromagnetic layer 111, a magnetic layer 112, and a non-magnetic intermediate layer 113 formed in sequence in a direction away from the seed layer 101. In this way, the magnetic layer 112 and the magnetic reference layer 103 are separated by the non-magnetic intermediate layer 113, and an independent input current may be configured or the input current may be shared. Based on the shared synthetic antiferromagnetic layer 102, a coupled nano-oscillator array may be formed by input phase locking, dipole interaction, etc., and adjacent nano-oscillators may be phase locked to gain output current.

[0048] Among them, the antiferromagnetic layer 111 can be any one of materials such as IrMn, Mn3Pt, Mn3Se, etc., the magnetic layer 112 can be one or more of materials such as CoFe, CoFeB, Co, NiFe, etc., and the non-magnetic intermediate layer 113 can be any one of metals such as Ru, W, Cu, etc.

[0049] The material of the magnetic free layer 105 and the material of the magnetic reference layer 103 can be any one of ferromagnetic, antiferromagnetic, ferrimagnetic, synthetic antiferromagnetic, synthetic ferrimagnetic, synthetic ferromagnetic, etc. The material of the non-magnetic insulating barrier layer 104 can include any one of MgO, AlOx, etc.

[0050] The cap layer 106 may be used to protect the magnetic free layer 105 , and the material of the cap layer 106 may include one or more metals such as tantalum (Ta), ruthenium (Ru), and platinum (Pt).

[0051] Embodiment 2

[0052] Please refer to Figure 3 , is a schematic diagram of the structure of another nano-oscillator array based on spin transfer torque provided by the present application, such as Figure 3 As shown, the nano-oscillator array includes: a seed layer 201 (which can be used as a bottom electrode layer); a magnetic free layer 202 formed on the seed layer 201; a non-magnetic insulating barrier layer 203 formed on the magnetic free layer 202; a magnetic reference layer 204 formed on the non-magnetic insulating barrier layer 203; a synthetic antiferromagnetic layer 205 formed on the magnetic reference layer 204; and a cap layer 206 formed on the synthetic antiferromagnetic layer 205. When etching to form nano-pillars, the etching can be terminated on the non-magnetic insulating barrier layer 203 by an endpoint detection method. One nano-pillar forms one nano-oscillator. Among them, the magnetic free layer 202 and the non-magnetic insulating barrier layer 203 can be collectively referred to as the first magnetic film layer mentioned above; the magnetic reference layer 204 and the synthetic antiferromagnetic layer 205 can be collectively referred to as the second magnetic film layer.

[0053] In the spin-transfer torque nano-oscillator array provided in this embodiment, each nano-pillar forms a nano-spin oscillator, and multiple nano-oscillators share the non-magnetic insulating barrier layer 203 and the magnetic free layer 202, and can form a coupled nano-oscillator array through spin waves 206, input phase locking, dipole interaction, etc. Adjacent nano-spin oscillators are coupled together through dipole action, input phase locking, etc. to form a coupled nano-oscillator array, thereby improving the coupling strength of the nano-oscillator array. When etching to form nano-pillars, the etching is terminated on the non-magnetic insulating barrier layer 203, which greatly reduces the shunting of the in-plane current in the cap layer 206 and improves the effective current density of the nano-oscillator.

[0054] It should be noted that each nano-oscillator can be configured with an independent input current or a shared input current, and adjacent nano-oscillators can perform current phase locking and gain current output.

[0055] Specifically, the synthetic antiferromagnetic layer 205 may include a non-magnetic intermediate layer 211, a magnetic layer 212, and an antiferromagnetic layer 213 formed in sequence in a direction away from the seed layer 201. In this way, the non-magnetic intermediate layer 211 separates the magnetic reference layer 204 and the magnetic layer 212 of the synthetic antiferromagnetic layer 205, and an independent input current may be configured, or an input current may be shared.

[0056] Among them, the antiferromagnetic layer 213 can be any one of materials such as IrMn, Mn3Pt, Mn3Se, etc., the magnetic layer 212 can be one or more of materials such as CoFe, CoFeB, Co, NiFe, etc., and the non-magnetic intermediate layer 211 can be any one of metals such as Ru, W, Cu, etc.

[0057] The material of the magnetic free layer 202 and the material of the magnetic reference layer 204 can be any one of ferromagnetic, antiferromagnetic, ferrimagnetic, synthetic antiferromagnetic, synthetic ferrimagnetic, synthetic ferromagnetic, etc. The material of the non-magnetic insulating barrier layer 203 can include any one of MgO and AlOx.

[0058] The cap layer 206 may be used to protect the magnetic free layer 202 , and the material of the cap layer 206 may include one or more metals such as tantalum (Ta), ruthenium (Ru), and platinum (Pt).

[0059] Embodiment 3

[0060] Please refer to Figure 4 , is a schematic flow chart of a method for preparing a nano-oscillator array provided in the present application, and the preparation method can be used to prepare the nano-oscillator array provided in Example 1 or Example 2, such as Figure 4 As shown, the preparation method may include the following steps:

[0061] Step S1, depositing a film stack and a hard mask of a nano-oscillator array on a substrate in sequence; the film stack is used to form a seed layer, a nano-column common layer and a nano-column array of the nano-oscillator array;

[0062] Step S2, forming a first mask pattern on the hard mask, and performing a first etching on the film stack based on the hard mask having the first mask pattern, etching to the upper surface of the seed layer;

[0063] Step S3, forming a second mask pattern on the hard mask, and performing a second etching on the film stack based on the hard mask having the second mask pattern, until the etching reaches the nano-column common layer.

[0064] It can be understood that the structure of the membrane stack of the above-mentioned nano-oscillator array can be any implementation in the above-mentioned embodiment 1 or embodiment 2, and this embodiment does not make any specific limitation to this.

[0065] The method for preparing the nano oscillator array provided in this embodiment can prepare the nano oscillator array provided in the first or second embodiment, and can at least achieve the beneficial effects of the nano oscillator array provided in the first or second embodiment, which will not be described in detail here.

[0066] It should be noted that the above steps S1 to S3 do not constitute a limitation to this embodiment. After the second etching is completed, Figure 5 As shown, an insulating protective layer can also be grown in situ, and after the insulating protection is performed, the sample can be subjected to chemical mechanical polishing to remove the remaining hard mask and other steps. Afterwards, a third mask pattern can be formed on the film stack of the nano-oscillator, and the insulating protective layer can be subjected to a third etching using the third mask pattern to open the through hole of the bottom electrode layer; and then the electrode can be grown through the evaporation process.

[0067] Embodiment 4

[0068] Please refer to Figure 6 , is a schematic diagram of the structure of an oscillating network provided in this application, such as Figure 6 As shown, the oscillation network may include a microwave conductor and a nano-oscillator array of the nano-oscillator array provided in the first or second embodiment; the microwave conductor generates a corresponding magnetic field based on the input microwave signal to be processed, and the magnetic field is coupled with the nano-oscillator array; the nano-oscillator array generates a corresponding oscillation frequency based on different input currents, and the nano-oscillators in the nano-oscillator array whose oscillation frequency matches the frequency of the microwave signal are phase-locked.

[0069] The oscillating network provided in this embodiment, including the spin transfer torque nano-oscillator array provided in the first or second embodiment, can at least achieve the beneficial effects of the nano-oscillator array provided in the first or second embodiment, which will not be described in detail here. It can also complete tasks such as speech and image recognition.

[0070] In a specific embodiment, each row of nano-oscillators shares the same input current, and the nano-oscillators in the same row phase-lock gain output. Different rows of spin nano-oscillators have different input currents and different oscillation frequencies. The image and voice waiting recognition signal is encoded into a microwave signal f A +f B The input microwave wire 401 generates an Oersted field (ie, a magnetic field) that couples with the spin nano-oscillator array. The spin nano-oscillator with the same oscillation frequency as the input microwave signal will be phase-locked with the input, so that the output is enhanced, that is, the oscillation network recognizes a specific input.

[0071] In another embodiment, each nano-oscillator has an independent current, and the output of the nano-spin oscillator is enhanced by being frequency-locked to the microwave signal, i.e., the oscillating network recognizes a specific input.

[0072] Embodiment 5

[0073] Please refer to Figure 7 , is a schematic diagram of the structure of a storage pool computing device based on a nano-oscillator array provided in this application, such as Figure 7 As shown, the reserve pool computing device may include: an input layer and an output layer, and an oscillator reserve pool composed of the nano-oscillator array provided in Example 1 or Example 2, the oscillator reserve pool is arranged between the input layer and the output layer; the input layer is used to inject the pulse signal of the signal to be processed into the oscillator reserve pool; the nano-oscillators in the oscillator reserve pool are coupled with each other to map the pulse signal of the signal to be processed to a higher-dimensional state space to generate high-dimensional feature data; the output layer is used to linearly output the high-dimensional feature data.

[0074] The input layer can encode samples of speech, images, video signals, etc. into a pulse sequence with a certain amplitude, and then input the pulse sequence into a reserve pool composed of a spin transfer torque nano-oscillator array. The oscillators in the spin transfer torque nano-oscillator array of the reserve pool are coupled through spin waves, dipole interactions, and input phase locking. The reserve pool responds to each input, continuously adjusting the linear weight between the reserve pool and the output layer to produce the correct output.

[0075] The reserve pool computing device provided in this embodiment includes a reserve pool composed of the spin transfer torque nano-oscillator array provided in the first or second embodiment, which can at least achieve the beneficial effects of the nano-oscillator array provided in the first or second embodiment, which will not be described in detail here. It can also efficiently and accurately process and calculate voice, image, video signals, etc., improving the computing power and robustness of the reserve pool computing device in the fields of neuromorphic computing, communication systems, etc.

[0076] The preferred specific embodiments of the present invention are described in detail above. It should be noted that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A nano-oscillator array based on spin transfer torque, characterized in that: It comprises a seed layer and a nanocolumn common layer and a nanocolumn array formed in sequence in a direction away from the seed layer; the nanocolumn common layer comprises at least a first magnetic film layer; The nanocolumn array includes a plurality of nanocolumns arranged in an array, each of the nanocolumns corresponding to a nanospin oscillator; each of the nanocolumns includes a second magnetic film layer and a cap layer sequentially arranged in a direction away from the seed crystal layer.

2. The nano-oscillator array according to claim 1, characterized in that: The first magnetic film layer includes a synthetic antiferromagnetic layer; The second magnetic film layer includes a magnetic reference layer, a nonmagnetic insulating barrier layer, and a magnetic free layer which are sequentially formed in a direction away from the first magnetic film layer.

3. The nano-oscillator array according to claim 2, characterized in that: The synthetic antiferromagnetic layer includes an antiferromagnetic layer, a magnetic layer and a non-magnetic intermediate layer which are sequentially formed in a direction away from the seed crystal layer.

4. The nano-oscillator array according to claim 1, characterized in that: The first magnetic film layer includes a magnetic free layer and a non-magnetic insulating barrier layer; The second magnetic film layer includes a magnetic reference layer and a synthetic antiferromagnetic layer which are sequentially formed in a direction away from the first magnetic film layer.

5. The nano-oscillator array according to claim 4, characterized in that: The synthetic antiferromagnetic layer includes a non-magnetic intermediate layer, a magnetic layer and an antiferromagnetic layer which are sequentially formed in a direction away from the seed crystal layer.

6. The nano-oscillator array according to claim 3 or 5, characterized in that: The material of the antiferromagnetic layer includes any one of iridium-manganese alloy, manganese-platinum alloy and manganese-selenium alloy; the material of the magnetic layer includes one or more of cobalt-iron alloy, cobalt-iron-boron alloy, metal cobalt and nickel-iron alloy; the material of the non-magnetic intermediate layer includes any one of metal ruthenium, metal tungsten and metal copper.

7. The nano-oscillator array according to claim 3 or 5, characterized in that: The material of the magnetic free layer and the material of the magnetic reference layer are any one of ferromagnetism, antiferromagnetism, ferrimagnetism, synthetic antiferromagnetism, synthetic ferrimagnetism and synthetic ferromagnetism.

8. The nano-oscillator array according to claim 3 or 5, characterized in that: The material of the non-magnetic insulating barrier layer includes magnesium oxide or aluminum oxide.

9. The nano-oscillator array according to any one of claims 1 to 5, characterized in that: The material of the capping layer includes one or more of metal tantalum, metal ruthenium and metal platinum.

10. A method for preparing a nano-oscillator array, characterized in that: For preparing the nano-oscillator array according to any one of claims 1 to 9, the method comprises: Depositing a film stack and a hard mask of the nano-oscillator array on a substrate in sequence; the film stack is used to form a seed layer, a nano-column common layer and a nano-column array of the nano-oscillator array; forming a first mask pattern on the hard mask, and performing a first etching on the film stack based on the hard mask having the first mask pattern, etching to the upper surface of the seed layer; A second mask pattern is formed on the hard mask, and the film stack is second-etched based on the hard mask having the second mask pattern until the nanorod common layer is etched.

11. An oscillating network, characterized in that: A nano-oscillator array comprising a microwave conductor and any one of claims 1 to 9; The microwave wire generates a corresponding magnetic field based on the input microwave signal to be processed, and the magnetic field is coupled with the nano-oscillator array; The nano-oscillator array generates corresponding oscillation frequencies based on different input currents, and the nano-oscillators in the nano-oscillator array whose oscillation frequencies match the frequency of the microwave signal are phase-locked.

12. A reservoir computing device based on a nano-oscillator array, characterized in that: include: An input layer and an output layer, and an oscillator reserve pool formed by the nano-oscillator array according to any one of claims 1 to 9, wherein the oscillator reserve pool is arranged between the input layer and the output layer; The input layer is used to inject the pulse signal of the signal to be processed into the oscillator reserve pool; The nano-oscillators in the oscillator reserve pool are coupled to each other, mapping the pulse signal of the signal to be processed to a higher-dimensional state space to generate high-dimensional feature data; The output layer is used to linearly output the high-dimensional feature data.

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