Artificially synthesized antiferromagnetic device film layer and interlayer chiral coupling detection method thereof

Abstract

The invention provides an artificially synthesized antiferromagnetic device film layer and an interlayer chiral coupling detection method thereof. The corresponding device film layer comprises an upper magnetic layer, a lower magnetic layer and a middle non-magnetic layer, the magnetic moment difference value of the upper magnetic layer and the lower magnetic layer is greater than a preset value, so that a hysteresis loop of the device film layer comprises three turns. The corresponding interlayer chiral coupling detection method comprises the following steps: acquiring a hysteresis loop of a device film layer corresponding to a magnetic field additionally applied along two phase angles in a plane; the hysteresis loops corresponding to the two phase angles are calibrated according to the at least one side loop corresponding to the two phase angles; and detecting the interlayer chiral coupling property of the film layer of the device according to the hysteresis loop corresponding to the two calibrated phase angles. According to the invention, the overturning sequence of the upper and lower magnetic layers can be changed, so that the offset of the hysteresis loop caused by the interlayer DMI can be obviously amplified when the upper and lower layers are overturned at the same time, and the error caused by the inaccurate magnetic field angle can be eliminated through the hysteresis loop calibration.

Description

Technical Field

[0001] The present application relates to the field of spin electronics technology, in particular to the technical field of the interaction between spin electronics and magnetic measurement, and specifically to an artificially synthesized antiferromagnetic device film layer and a method for detecting chiral coupling between layers thereof. Background Art

[0002] With the rapid development of emerging technologies such as 5G, big data, the Internet of Things, and cloud computing, Moore's Law, which is used to guide the process of complementary metal oxide semiconductor (CMOS) integrated circuits, has reached its limit and is difficult to meet the needs of massive information processing. At the same time, spin electronics technology, which uses electron spin instead of charge as an information carrier, continues to make breakthroughs in materials and devices. Because of its advantages such as non-volatility, low power consumption, and high-speed writing, it is considered to be a technology with great potential to solve the power consumption bottleneck of integrated circuits in the "post-Moore" era. Spin electronics mainly studies the characteristics of the spin freedom of electrons and their manipulation methods, and realizes a new generation of electronic devices by generating, regulating, transporting, and detecting spin currents.

[0003] In the detection of interlayer chiral coupling, namely interlayer DMI, the mainstream method is asymmetric hysteresis loop measurement. Usually, the hysteresis loop reversal of synthetic antiferromagnet (SAF) should be completely symmetrical under positive and negative sweeping fields. When there is an interlayer (Dzyaloshinskii-Moriya Interaction, DMI) in the system, there will be an in-plane bias field in the SAF, and the direction of the bias field varies with the different magnetization arrangement of the SAF. In order to measure this direction-variable bias field, the researchers will additionally apply a constant direction bias field in the in-plane direction. Accordingly, these two fields will assist or hinder the magnetization reversal of the SAF in the same or opposite directions, respectively. Using this principle, the researchers found that by applying a positive or negative in-plane bias field, the SAF, under the combined action of the interlayer DMI and the in-plane field, the behavior of the magnetization reversal being assisted or hindered will further manifest as the overall left or right shift of the hysteresis loop, and the shift can be used to characterize the magnitude of the interlayer DMI effective field in the system. However, at present, there are still two important problems to be solved in detecting interlayer DMI in this way:

[0004] 1. It is difficult to extract the interlayer DMI signal. Due to the small magnitude of the interlayer DMI, the overall offset is small, generally showing as an offset of 1-2mT on the hysteresis loop. The reversal field of the hysteresis loop is usually tens to hundreds of mT, which leads to a small signal-to-noise ratio when extracting the interlayer DMI effective field, and the signal extraction is inaccurate.

[0005] 2. Due to the angle setting error when the sample is installed (or the error caused by the inaccurate magnetic field direction) and the hysteresis of the rotating stage, small loop offset errors will occur, which cannot be eliminated by the existing technology. Summary of the invention

[0006] The present invention provides an artificially synthesized antiferromagnetic device film layer and a matching interlayer chiral coupling detection method to solve the following problems in the prior art: difficulty in extracting interlayer DMI signals; and small loop offset errors caused by angle setting errors during sample installation (or errors caused by inaccurate magnetic field direction) and hysteresis of the rotating stage.

[0007] In order to solve at least one of the above problems existing in the prior art, an embodiment of the present application provides an artificial antiferromagnetic device film layer and a method for detecting chiral coupling between layers thereof.

[0008] According to a first aspect of an embodiment of the present application, the present application provides an artificially synthesized antiferromagnetic device film layer, comprising:

[0009] an upper magnetic layer, a lower magnetic layer, and a middle non-magnetic layer;

[0010] The upper magnetic layer and the lower magnetic layer are respectively attached to two sides of the middle non-magnetic layer;

[0011] The difference in magnetic moment between the upper magnetic layer and the lower magnetic layer is greater than a preset value, so that the hysteresis loop of the device film layer includes three reversals; wherein each reversal corresponds to a portion of the hysteresis loop perpendicular to the magnetic flux density coordinate line.

[0012] In some embodiments of the present application, the upper magnetic layer and the lower magnetic layer are made of different materials.

[0013] In some embodiments of the present application, the saturation magnetization intensities of the upper magnetic layer and the lower magnetic layer are different.

[0014] In some embodiments of the present application, the thickness of the upper magnetic layer is different from that of the lower magnetic layer.

[0015] In some embodiments of the present application, the materials of the upper magnetic layer and the lower magnetic layer include: one or more of barium ferrite, iron, cobalt, nickel, cobalt iron boron, nickel iron, lanthanum strontium manganese oxide, strontium ruthenate and Schler alloy.

[0016] In some embodiments of the present application, the material of the intermediate non-magnetic layer includes: one or more of platinum, tantalum, iridium, ruthenium and silver.

[0017] According to a second aspect of an embodiment of the present application, the present application provides a method for detecting interlayer chiral coupling of a synthetic antiferromagnetic device film layer as described in the first aspect, the method comprising:

[0018] Obtaining a hysteresis loop of the device film layer corresponding to applying a magnetic field at two additional phase angles in the plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a central loop located in the middle and two side loops located on both sides of the central loop;

[0019] Calibrate the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles;

[0020] The interlayer chiral coupling property of the device film layer is detected according to the hysteresis loops corresponding to the two calibrated phase angles.

[0021] In some embodiments of the present application, calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles includes:

[0022] Determine the center line of at least one side loop corresponding to the two phase angles respectively; wherein the center line is a parallel line of two sides of the side loop that are perpendicular to the direction of the magnetic flux density coordinate line, and the distance between the parallel line and the two sides is equal;

[0023] The hysteresis loop corresponding to the at least one phase angle is moved so that the center lines of the hysteresis loops corresponding to the two phase angles coincide with each other.

[0024] In some embodiments of the present application, detecting the interlayer chiral coupling property of the device film layer according to the hysteresis loops corresponding to the two calibrated phase angles includes:

[0025] The magnitude of the interlayer chiral coupling field is determined according to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles.

[0026] In some embodiments of the present application, determining the magnitude of the interlayer chiral coupling field according to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles includes:

[0027] Determine two same side edges corresponding to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles; wherein the same side edges are perpendicular to the direction of the magnetic flux density coordinate line;

[0028] Determine the difference in magnetic field magnitude between two same-side edges;

[0029] The magnitude of the interlayer chiral coupling field is determined according to the difference in magnitude of the magnetic field.

[0030] In a third aspect, the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of a method for detecting interlayer chiral coupling of an artificial synthetic antiferromagnetic device film layer.

[0031] In a fourth aspect, the present invention provides an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of a method for detecting interlayer chiral coupling of an artificially synthesized antiferromagnetic device film layer are implemented.

[0032] In a fifth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a method for detecting interlayer chiral coupling of a film layer of an artificially synthesized antiferromagnetic device.

[0033] From the above description, it can be seen that an embodiment of the present invention provides an artificial antiferromagnetic device film layer and an interlayer chiral coupling detection method thereof, and the corresponding artificial antiferromagnetic device film layer includes: an upper magnetic layer, a lower magnetic layer and an intermediate non-magnetic layer; the upper magnetic layer and the lower magnetic layer are respectively attached to the two sides of the intermediate non-magnetic layer; the magnetic moment difference between the upper magnetic layer and the lower magnetic layer is greater than a preset value, so that the hysteresis loop of the device film layer contains three reversals; wherein each reversal corresponds to the part of the hysteresis loop perpendicular to the direction of the magnetic flux density coordinate line.

[0034] The corresponding interlayer chiral coupling detection method includes: first, obtaining the hysteresis loop of the device film layer corresponding to the magnetic field applied along two phase angles in the plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a middle loop located in the middle and two side loops located in the middle; then, calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles; finally, detecting the interlayer chiral coupling properties of the device film layer according to the hysteresis loops corresponding to the two calibrated phase angles.

[0035] The synthetic antiferromagnetic device film layer and the interlayer chiral coupling detection method thereof proposed in the embodiment of the present invention can change the flip sequence of the upper and lower magnetic layers by increasing the difference between the upper and lower magnetic layers, saturation magnetization or thickness of the synthetic antiferromagnetic material. Thus, the offset of the hysteresis loop caused by the interlayer DMI will be significantly amplified when the upper and lower layers flip at the same time, and the error caused by the inaccurate magnetic field angle can be eliminated by calibrating the hysteresis loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0037] Figure 1 This is a schematic diagram of the structure of the artificial antiferromagnetic device film layer of an embodiment of the present application.

[0038] Figure 2 This is a schematic diagram of the results of the interlayer chiral coupling detection of the artificial antiferromagnetic device film layer of the embodiment of the present application (one phase angle).

[0039] Figure 3 The diagram is a structural diagram of a film layer of an artificially synthesized antiferromagnetic device in the prior art.

[0040] Figure 4 A schematic diagram of the results of interlayer chiral coupling detection of the film layer of an artificially synthesized antiferromagnetic device in the prior art (one phase angle).

[0041] Figure 5 It is a schematic flow chart of the interlayer chiral coupling method of the artificially synthesized antiferromagnetic device film layer according to an embodiment of the present application.

[0042] Figure 6 This is a schematic diagram of the results of the interlayer chiral coupling detection of the artificial antiferromagnetic device film layer of the embodiment of the present application (two phase angles).

[0043] Figure 7 It is a flow chart of step 200 of the method for interlayer chiral coupling of artificially synthesized antiferromagnetic device films according to an embodiment of the present application.

[0044] Figure 8 It is a flow chart of step 300 of the method for interlayer chiral coupling of artificially synthesized antiferromagnetic device films according to an embodiment of the present application.

[0045] Fig. 9 It is a flow chart of step 301 of the method for interlayer chiral coupling of artificially synthesized antiferromagnetic device films according to an embodiment of the present application.

[0046] Fig.10 It is a schematic flow chart of a method for interlayer chiral coupling of artificially synthesized antiferromagnetic device films according to a specific embodiment of the present application.

[0047] Fig.11 It is a schematic diagram of the structure of an electronic device in an embodiment of the present invention.

[0048] Reference numerals:

[0049] 83: magnetic layer (artificially synthesized antiferromagnetic device film layer in the prior art);

[0050] 84: middle non-magnetic layer (artificially synthesized antiferromagnetic device film layer in the prior art);

[0051] 85: magnetic layer (artificially synthesized antiferromagnetic device film layer in the prior art, with a magnetic moment close to that of 83);

[0052] 86: magnetic layer (the device film layer of artificially synthesized antiferromagnetic in this application);

[0053] 87: middle non-magnetic layer (artificially synthesized antiferromagnetic device film layer in this application);

[0054] 88: magnetic layer (the device film layer of artificially synthesized antiferromagnetic in this application. It has a large difference in magnetic moment from 86); DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0057] It should be noted that the terms "including" and "having" in the specification and claims of the present application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. In the absence of conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0058] In order to solve at least one of the above-mentioned problems existing in the prior art, in a first aspect, an embodiment of the present application provides an artificial antiferromagnetic device film layer. Figure 1 Schematic diagram of the device film layer of the artificially synthesized antiferromagnetic device of the embodiment of the present application. Figure 1 As shown, the device film layer of artificial antiferromagnetic includes:

[0059] an upper magnetic layer 86, a lower magnetic layer 88 and an intermediate non-magnetic layer 87;

[0060] The upper magnetic layer 86 and the lower magnetic layer 88 are respectively attached to both sides of the middle non-magnetic layer 87 ( Figure 1 The middle refers to the upper and lower sides);

[0061] The magnetic moment difference between the upper magnetic layer 86 and the lower magnetic layer 88 is greater than a preset value, so that the hysteresis loop of the device film layer includes three reversals; wherein each reversal corresponds to a portion of the hysteresis loop perpendicular to the magnetic flux density coordinate line.

[0062] Here Figure 2 Take the above “three flips” as an example to explain Figure 2 In the figure, the red curve is the change of the anomalous Hall resistance obtained by applying a positive internal magnetic field (or called a positive magnetic field, that is, the magnetic field sweeps from negative to positive) to the device film layer (that is, the change curve of the anomalous Hall resistance in the process of the magnetic field corresponding to the horizontal axis changing from negative to positive, μ0 is the magnetic induction constant, H z is the magnetic field strength, that is, the horizontal axis μ0H z is the scanning magnetic field in the z direction), and correspondingly, the black curve is the change diagram of the anomalous Hall resistance obtained by applying a negative internal magnetic field to the device film layer. For the two processes of applying a positive internal magnetic field and a negative internal magnetic field to the device film layer, each process has three flips, and each flip corresponds to the part of the hysteresis loop perpendicular to the magnetic flux density coordinate line. For the red curve, the three flips correspond to 1, 2 and 3 in the figure, and for the gray curve, the three flips correspond to 4, 5 and 6 in the figure.

[0063] It should be pointed out that the portion of the hysteresis loop perpendicular to the direction of the magnetic flux density coordinate line is roughly perpendicular to the direction of the magnetic flux density coordinate line, or can be understood as the portion of the hysteresis loop that changes in the horizontal direction.

[0064] In order to compare with the artificial antiferromagnetic device film layer in the prior art, the present application also shows the hysteresis loop corresponding to the traditional artificial antiferromagnetic device film layer, see Figure 3The core film layer is composed of the middle non-magnetic layer 84 and the two ferromagnetic layers 83 and 85 separated by it. The material, saturation magnetization intensity and thickness of the upper and lower ferromagnetic layers are similar. The flip curve caused by this is Figure 4 Specifically, see Figure 4 For the hysteresis loop of each phase angle (the red curve is the hysteresis loop corresponding to a phase angle of 180°, and the black curve is the hysteresis loop corresponding to a phase angle of 0°), it has two flips, i.e., two parts roughly perpendicular to the direction of the magnetic flux density coordinate line, which is obviously different from the present application.

[0065] From the above description, it can be seen that an embodiment of the present invention provides an artificial antiferromagnetic device film layer, including: an upper magnetic layer, a lower magnetic layer and an intermediate non-magnetic layer; the upper magnetic layer and the lower magnetic layer are respectively attached to the two sides of the intermediate non-magnetic layer; the magnetic moment difference between the upper magnetic layer and the lower magnetic layer is greater than a preset value, so that the hysteresis loop of the device film layer contains three reversals; wherein each reversal corresponds to the part of the hysteresis loop perpendicular to the direction of the magnetic flux density coordinate line.

[0066] In view of the difficulties in signal extraction and error elimination faced by the current interlayer chiral coupling detection mentioned in the above background, the artificial synthetic antiferromagnetic device film layer proposed in the embodiment constructs an artificial synthetic ferrimagnetic system to detect interlayer exchange coupling by optimizing the material, saturation magnetization intensity or thickness of one layer. Due to the change in the magnetic layer flip sequence, the error caused by the inaccurate magnetic field angle can be eliminated and the interlayer chiral exchange coupling signal can be amplified by about 10 times.

[0067] In some embodiments of the present application, the method of making the magnetic moment difference between the upper magnetic layer and the lower magnetic layer greater than a preset value includes at least one of the following: optimizing the material, saturation magnetization intensity or thickness of one of the upper magnetic layer and the lower magnetic layer.

[0068] In some embodiments of the present application, the materials of the upper magnetic layer and the lower magnetic layer include: barium ferrite (BAM), iron (Fe), cobalt (Co), nickel (Ni), cobalt iron boron (CoFeB), nickel iron (NiFe), lanthanum strontium manganese oxide (LSMO), strontium ruthenate (SrRuO3), Schler alloy or one or more other ferromagnetic materials.

[0069] In some embodiments of the present application, the material of the intermediate non-magnetic layer includes: one or more of various metal non-magnetic materials such as platinum (Pt), tantalum (Ta), iridium (Ir), ruthenium (Ru), silver (Ag), etc.

[0070] Preferably, the intermediate non-magnetic layer introduces symmetry breaking in the in-plane direction by wedge-shaped or oblique target sputtering.

[0071] On the other hand, the embodiment of the present invention also provides a method for detecting interlayer chiral coupling of a synthetic antiferromagnetic device film layer. Specifically, see Figure 5 , the method includes:.

[0072] Step 100: obtaining a hysteresis loop of a device film layer corresponding to a magnetic field applied at two phase angles in an additional plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a central loop located in the middle and two side loops located on both sides of the central loop;

[0073] Step 200: calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles;

[0074] Step 300: detecting the interlayer chiral coupling property of the device film layer according to the hysteresis loops corresponding to the two calibrated phase angles.

[0075] From the above description, it can be seen that an embodiment of the present invention provides an interlayer chiral coupling detection method, including: first, obtaining the hysteresis loop of the device film layer corresponding to the magnetic field applied along two phase angles in the plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a central loop located in the middle and two side loops located in the middle; then, calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles; finally, detecting the interlayer chiral coupling properties of the device film layer according to the hysteresis loops corresponding to the two phase angles after calibration.

[0076] As can be seen from the above description, in order to solve the technical problems in the background technology, the present application provides different detection methods to obtain the interlayer chiral coupling effective field. The upper and lower ferromagnetic layers of the artificial synthetic antiferromagnetism are very close in terms of material, thickness and saturation magnetization. When the difference in the magnetic moment of the upper and lower ferromagnetic layers becomes larger, the magnetic system is transformed into an artificial synthetic ferrimagnetism. Further, when this difference becomes significant, the magnetic layer reversal sequence of the artificial synthetic ferrimagnetism will change, and the influence of the interlayer DMI on the hysteresis loop will no longer appear as an overall hysteresis loop offset. Using artificial synthetic ferrimagnetism with a large difference in magnetic moment to detect the interlayer DMI, not only can the error caused by the inaccurate magnetic field angle be eliminated through self-calibration, but the offset of the center loop caused by it will also be significantly amplified by about 10 times. These two advantages make it an efficient interlayer chiral coupling detection method.

[0077] For step 100, the hysteresis loop represents a closed magnetization curve of the hysteresis phenomenon of the ferromagnetic material when the magnetic field intensity changes periodically. It shows the relationship between the magnetization intensity or magnetic induction intensity and the magnetic field intensity during the repeated magnetization process of the ferromagnetic material.

[0078] See also Figure 2Based on the synthetic antiferromagnetic device film provided by the present application, in one magnetic field scanning direction, the magnetization reversal of the device film layer is correspondingly transformed into a three-step reversal. In one magnetic field scanning direction, the device reversal has three steps, and the reversal order is the lower layer reversing once, the two layers reversing at the same time, and the lower layer reversing once.

[0079] The hysteresis loop corresponding to each phase angle contains three closed areas (the middle loop 7 and two side loops 8 and 9 located in the middle loop). Figure 4 By comparison, the difference can be clearly seen, that is, the area, number and shape of the closed areas are different.

[0080] In addition, the two phase angles may be 0° and 180°, or 112.5° and 292.5°, that is, the difference between the two phase angles is 180°.

[0081] As for step 200, it can be seen from the above description that in one magnetic field scanning direction, the device flips in three steps, and the flipping order is flipping the lower layer once, flipping both layers at the same time, and flipping the lower layer again. In this case, the effect of interlayer DMI on magnetization flipping is no longer an overall offset. From the overall relative performance of the hysteresis loop, the positive or reverse application of the in-plane magnetic field will cause the three small loops (the middle loop and the two measuring loops) to show expansion-offset-contraction in turn. Among them, due to the double-layer flipping, the offset of the middle loop Δμ0H SW Obviously magnified by about 10 times (see Figure 6 ). At the same time, since the side loop shows expansion or contraction instead of offset, the center of the side loop can be cleverly used as a reference line to calibrate the two hysteresis loops and eliminate the error caused by the inaccurate magnetic field angle.

[0082] The interlayer chiral coupling effect in step 300, namely, the interlayer Dzyaloshinskii-Moriya Interaction (DMI), tends to make the magnetization of the upper and lower ferromagnetic layers separated by the middle layer show chiral vertical arrangement.

[0083] In some embodiments of the present application, see Figure 7 , step 200 comprises:

[0084] Step 201: respectively determining the center line of at least one side loop corresponding to the two phase angles; wherein the center line is a parallel line of two sides of the side loop perpendicular to the direction of the magnetic flux density coordinate line, and the distance between the parallel line and the two sides is equal;

[0085] See also Figure 6Here, the side loop on the left is taken as an example. The green dotted line in the figure is the center line of the side loop (the center lines of the side loops corresponding to the two phase angles in the figure have overlapped, that is, they have been calibrated, so they are displayed as one line in the figure). The center line is parallel to the black line edges and red line edges on both sides, and its distance from the black line edges on both sides is equal, and the distance from the two red line edges is equal.

[0086] It is understandable that the hysteresis loop calibration may also be performed based on the center line of the side loop on the right side, and the present application is not limited thereto.

[0087] Step 202: Move the hysteresis loop corresponding to the at least one phase angle so that the center lines of the hysteresis loops corresponding to the two phase angles coincide with each other.

[0088] It can be understood that the hysteresis loop corresponding to any one phase angle can be moved so that the center lines of the hysteresis loops corresponding to the two phase angles coincide, or the hysteresis loops corresponding to the two phase angles can be moved at the same time so that the center lines of the hysteresis loops corresponding to the two phase angles coincide. The present application is not limited to this.

[0089] In some embodiments of the present application, see Figure 8 , step 300 comprises:

[0090] Step 301: Determine the magnitude of the interlayer chiral coupling field according to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles.

[0091] In some embodiments of the present application, see Fig. 9 , step 301 comprises:

[0092] Step 3011: determining two same side edges corresponding to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles; wherein the same side edges are perpendicular to the direction of the magnetic flux density coordinate line;

[0093] See also Figure 6 The two same sides are respectively at the positions shown in 10 and 11 in the figure, and of course, the positions shown in 12 and 13 in the figure can also be selected.

[0094] Step 3012: Determine the difference in magnetic field magnitude between two same sides;

[0095] That is, the magnitude of the magnetic field corresponding to 11 in the figure is subtracted from the magnitude of the magnetic field corresponding to 10 in the figure; or, the magnitude of the magnetic field corresponding to 13 in the figure is subtracted from the magnitude of the magnetic field corresponding to 12 in the figure.

[0096] Step 3013: Determine the magnitude of the interlayer chiral coupling field according to the magnetic field magnitude difference.

[0097] Continue to see Figure 6The difference in magnetic field magnitude (or reversal field difference) in step 3012 is the offset of the overall hysteresis loop Δμ0H SW , which is the size of the interlayer chiral coupling field, and the offset Δμ0H is clearly seen SW It is obviously amplified by about 10 times, thus perfectly solving the technical pain point of difficult inter-layer DMI signal extraction in the prior art.

[0098] In order to further illustrate the scheme, a specific implementation method of an artificially synthesized antiferromagnetic device film layer and a method for detecting chiral coupling between layers thereof is also provided here, and specific reference is made to the following content:

[0099] The invention relates to a novel interlayer chiral coupling detection method, and belongs to the field of spin electronics and magnetic measurement.

[0100] In the field of spin electronics research, magnetic interaction research has always been the focus of researchers, and it is the cornerstone of building magnetic memory. Due to the combined advantages of ferromagnetism (high readability and writability) and antiferromagnetism (high dimensional miniaturization, thermal stability and speed), synthetic antiferromagnetism (SAF) has gradually become one of the research focuses in the field of spin electronics. To build SAF, the symmetric RKKY interaction is the most important basic role. Recently, the corresponding antisymmetric interlayer exchange interaction, namely the interlayer DMI, has also been verified theoretically and experimentally. RKKY tends to arrange the upper and lower magnetic moments in parallel or antiparallel, while the interlayer DMI tends to arrange the upper and lower magnetic moments in a certain clock direction vertically. The combination of the two can provide more possibilities for the construction of magnetic memory. In addition, the interlayer DMI can be used to realize a variety of applications in spin electronics, such as assisting the spin-orbit moment to achieve deterministic information writing and constructing a three-dimensional topological non-trivial spin structure Hopfion.

[0101] Figure 3 as well as Figure 4 Shown is the existing measurement scheme for interlayer DMI; Figure 1 as well as Figure 6 The device film layer structure provided in this application and the measurement results of its corresponding measurement scheme.

[0102] exist Figure 3 In the figure, the core film layer of the device is composed of a middle non-magnetic layer and two ferromagnetic layers separated by it. The material, saturation magnetization and thickness of the upper and lower ferromagnetic layers are similar. The flip curve caused by this is a two-step flip as shown in the figure. In one magnetic field scanning direction, the device flips in two steps, and the upper and lower ferromagnetic layers flip once each. When the in-plane magnetic field is applied in the positive or reverse direction, the overall hysteresis loop will shift to the left or right, and the offset Δμ0H SWIt is the size of the effective DMI field between layers. It can be seen that the offset is very small and the offset error introduced by the inaccurate magnetic field angle cannot be eliminated.

[0103] In contrast, the solution proposed in the present application is based on the existing solution, and by changing at least one of the material, saturation magnetization intensity or thickness of the lower ferromagnetic layer, a larger difference in the magnetic moment of the upper and lower layers is produced. The magnetization reversal of the device film layer is correspondingly converted into a three-step reversal. In a magnetic field scanning direction, the device film layer flips in three steps, and the reversal order is that the lower layer flips once, the two layers flip at the same time, and the lower layer flips again. In this case, the effect of the interlayer DMI on the magnetization reversal is no longer an overall offset. Judging from the overall relative performance of the loop, the positive or reverse application of the in-plane magnetic field will cause the three small loops to show expansion-offset-contraction in sequence. Among them, due to the double-layer reversal, the offset of the center loop Δμ0H SW It is obviously magnified by about 10 times. At the same time, since the side loop shows expansion or contraction rather than offset, the center of the side loop can be used as a reference line to calibrate the two hysteresis loops and eliminate the error caused by the inaccurate magnetic field angle.

[0104] It can be understood that the amplified offset of the hysteresis loop or the anomalous Hall effect loop is caused by the simultaneous flipping of the upper and lower layers. In the two-step flipping, the interlayer DMI effective field assists or hinders the magnetization flipping in the form of an in-plane field. Since the presence of the in-plane field helps to define the flipping direction of the ferromagnet and reduce the required energy barrier, when the interlayer DMI is parallel to the external in-plane field, it will always assist the flipping, and when the interlayer DMI is antiparallel to the external in-plane field, it will hinder the flipping. For the double-layer flipping in the three-step flipping, the interlayer DMI will directly compete with the scanning field in the form of a perpendicular field. Since the double layers are flipped simultaneously and the double layers are coupled in an antiferromagnetic form, the magnetic moments of the two layers will rotate in an antiparallel form and there is a situation where both rotate into the plane at the same time. At this time, the interlayer DMI effective field will point vertically upward or downward, and it is arranged parallel or antiparallel to the vertical scanning field, which greatly increases the degree of assistance or hindrance.

[0105] Specifically, see Fig.10 First, the artificial synthetic antiferromagnetic structure of the existing measurement scheme is improved. The magnetic moment of the lower magnetic layer is reduced by thinning the thickness of the lower magnetic layer (lower ferromagnetic layer), reducing the saturation magnetization intensity of the lower layer, or replacing the lower material, so as to increase the difference in magnetic moments between the upper and lower layers.

[0106] Next, the magnetic moment measurement or anomalous Hall effect measurement is performed on the corresponding artificial synthetic ferrimagnetic device to determine whether it has changed from a two-step flip to a three-step flip. If it has not changed, continue to perform the above operations. When the difference in magnetic moment between the upper and lower layers is large enough, the flipping process of the device will be transformed into a three-step flip. After the three-step flip is achieved, the asymmetric hysteresis loop of the device under the action of the interlayer DMI is measured. The specific method is to apply an additional in-plane field of fixed direction and magnitude during the process of measuring the hysteresis loop or the anomalous Hall effect loop with a vertical scanning field. Flipping the in-plane field can obtain two complete hysteresis loops. Further, the two hysteresis loops are calibrated with the center of the side loop as the reference line to eliminate errors caused by inaccurate magnetic field angles or other factors. Afterwards, the offset of the three-step flip center loop is measured. The offset is significantly amplified due to the simultaneous flipping of the upper and lower layers, which can characterize the size of the interlayer DMI effective field in the device. Finally, the interlayer chiral coupling measurement is completed.

[0107] From the above description, it can be seen that a specific embodiment of the present invention provides an interlayer chiral coupling detection method, including: first, obtaining the hysteresis loop of the device film layer corresponding to the magnetic field applied along two phase angles in the plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a middle loop located in the middle and two side loops located in the middle; then, calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles; finally, detecting the interlayer chiral coupling properties of the device film layer according to the hysteresis loops corresponding to the two phase angles after the calibration.

[0108] As can be seen from the above description, in order to solve the technical problems in the background technology, the present application provides different detection methods to obtain the interlayer chiral coupling effective field. The upper and lower ferromagnetic layers of the artificial synthetic antiferromagnetism are very close in terms of material, thickness and saturation magnetization. When the difference in the magnetic moment of the upper and lower ferromagnetic layers becomes larger, the magnetic system is transformed into an artificial synthetic ferrimagnetism. Further, when this difference becomes significant, the magnetic layer reversal sequence of the artificial synthetic ferrimagnetism will change, and the influence of the interlayer DMI on the hysteresis loop will no longer appear as an overall hysteresis loop offset. Using artificial synthetic ferrimagnetism with a large difference in magnetic moment to detect the interlayer DMI, not only can the error caused by the inaccurate magnetic field angle be eliminated through self-calibration, but the offset of the center loop caused by it will also be significantly amplified by about 10 times. These two advantages make it an efficient interlayer chiral coupling detection method.

[0109] The embodiments of the present application also provide a specific implementation of an electronic device capable of implementing all steps in the method for manufacturing the device film layer of the artificial synthetic antiferromagnetic device in the above embodiment, see Fig.11 , electronic equipment specifically includes the following:

[0110] Processor (processor) 1201, memory (memory) 1202, communication interface (CommunicationsInterface) 1203 and bus 1204;

[0111] The processor 1201, the memory 1202, and the communication interface 1203 communicate with each other through the bus 1204; the communication interface 1203 is used to realize information transmission between the server device and the client device and other related devices;

[0112] The processor 1201 is used to call the computer program in the memory 1202. When the processor executes the computer program, all the steps in the method for manufacturing the synthetic antiferromagnetic device film layer in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0113] Step 100: obtaining a hysteresis loop of a device film layer corresponding to applying a magnetic field at two additional phase angles in a plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a central loop located in the middle and two side loops located in the central loop;

[0114] Step 200: calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles;

[0115] Step 300: detecting the interlayer chiral coupling property of the device film layer according to the hysteresis loops corresponding to the two calibrated phase angles.

[0116] The embodiments of the present application also provide a computer-readable storage medium capable of implementing all the steps in the method for manufacturing a synthetic antiferromagnetic device film layer in the above embodiment. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, all the steps in the method for manufacturing a synthetic antiferromagnetic device film layer in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0117] Step 100: obtaining a hysteresis loop of a device film layer corresponding to applying a magnetic field at two additional phase angles in a plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a central loop located in the middle and two side loops located in the central loop;

[0118] Step 200: calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles;

[0119] Step 300: detecting the interlayer chiral coupling property of the device film layer according to the hysteresis loops corresponding to the two calibrated phase angles.

[0120] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the hardware + program embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0121] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0122] Although the present application provides method operation steps such as embodiments or flow charts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in the order of the method shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0123] For the convenience of description, the above devices are described in various modules according to their functions. Of course, when implementing the embodiments of this specification, the functions of each module can be implemented in the same or more software and / or hardware, or the module implementing the same function can be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0124] Those skilled in the art also know that, in addition to implementing the controller in a purely computer-readable program code, the controller can be made to implement the same function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered as a hardware component, and the devices for implementing various functions included therein can also be considered as structures within the hardware component. Or even, the devices for implementing various functions can be considered as both software modules for implementing the method and structures within the hardware component.

[0125] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0126] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0127] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of contradiction, a person skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0128] The above is only an example of the embodiment of the present specification and is not intended to limit the embodiment of the present specification. For those skilled in the art, the embodiment of the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiment of the present specification shall be included in the scope of the claims of the embodiment of the present specification.

Claims

1. An artificially synthesized antiferromagnetic device film layer, characterized in that: include: an upper magnetic layer, a lower magnetic layer, and a middle non-magnetic layer; The upper magnetic layer and the lower magnetic layer are respectively attached to two sides of the middle non-magnetic layer; The difference in magnetic moment between the upper magnetic layer and the lower magnetic layer is greater than a preset value, so that the hysteresis loop of the device film layer includes three reversals; wherein each reversal corresponds to a portion of the hysteresis loop perpendicular to the magnetic flux density coordinate line.

2. The device film layer according to claim 1, characterized in that: The upper magnetic layer and the lower magnetic layer are made of different materials.

3. The device film layer according to claim 1, characterized in that: The upper magnetic layer and the lower magnetic layer have different saturation magnetizations.

4. The device film layer according to claim 1, characterized in that: The upper magnetic layer and the lower magnetic layer have different thicknesses.

5. The device film layer according to claim 1, characterized in that: The materials of the upper magnetic layer and the lower magnetic layer include: one or more of barium ferrite, iron, cobalt, nickel, cobalt iron boron, nickel iron, lanthanum strontium manganese oxide, strontium ruthenate and Schler alloy.

6. The device film layer according to claim 1, characterized in that: The material of the intermediate non-magnetic layer includes one or more of platinum, tantalum, iridium, ruthenium and silver.

7. A method for detecting interlayer chiral coupling of an artificial antiferromagnetic device film layer according to any one of claims 1 to 6, characterized in that: include: Obtaining a hysteresis loop of the device film layer corresponding to applying a magnetic field at two additional phase angles in the plane; wherein the difference between the two phase angles is 180°, and the hysteresis loop includes a central loop located in the middle and two side loops located on both sides of the central loop; Calibrate the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles; The interlayer chiral coupling property of the device film layer is detected according to the hysteresis loops corresponding to the two calibrated phase angles.

8. The interlayer chiral coupling detection method according to claim 7, characterized in that: Calibrating the hysteresis loops corresponding to the two phase angles according to at least one side loop corresponding to the two phase angles, comprising: Determine the center line of at least one side loop corresponding to the two phase angles respectively; wherein the center line is a parallel line of two sides of the side loop that are perpendicular to the direction of the magnetic flux density coordinate line, and the distance between the parallel line and the two sides is equal; The hysteresis loop corresponding to the at least one phase angle is moved so that the center lines of the hysteresis loops corresponding to the two phase angles coincide with each other.

9. The interlayer chiral coupling detection method according to claim 7, characterized in that: The detecting the interlayer chiral coupling property of the device film layer according to the hysteresis loops corresponding to the two calibrated phase angles comprises: The magnitude of the interlayer chiral coupling field is determined according to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles.

10. The interlayer chiral coupling detection method according to claim 9, characterized in that: Determining the magnitude of the interlayer chiral coupling field according to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles includes: Determine two same side edges corresponding to the middle loop of the hysteresis loop corresponding to the two calibrated phase angles; wherein the same side edges are perpendicular to the direction of the magnetic flux density coordinate line; Determine the difference in magnetic field magnitude between two same-side edges; The magnitude of the interlayer chiral coupling field is determined according to the difference in magnitude of the magnetic field.

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