Planar magneton valve based on grid voltage regulation and control and electronic equipment comprising planar magneton valve

Abstract

The invention relates to a planar magneton valve sensor based on grid voltage regulation and control and electronic equipment comprising the planar magneton valve sensor. According to an embodiment, a core structure of a magneton magnetoresistance device may include: a first metal gate layer; a first ferromagnetic insulating layer (FMI1) disposed on the first metal gate electrode layer, and a second ferromagnetic insulating layer (FMI2) disposed on the first metal gate electrode layer; and an intermediate layer (Spacer) disposed on the first ferromagnetic insulating layer; and a second ferromagnetic insulating layer (FMI2) disposed on the non-magnetic intermediate layer, the first ferromagnetic insulating layer (FMI2) being disposed on the non-magnetic intermediate layer (FMI2), and the second ferromagnetic insulating layer (FMI2) being disposed on the non-magnetic intermediate layer (FMI2). And a second metal gate layer disposed on the second ferromagnetic insulating layer.

Description

Technical Field

[0001] The present invention generally relates to the field of magnonics and magnon-type devices, and more particularly to a planar magnon valve regulated based on a gate voltage and an electronic device comprising the planar magnon valve. Background Art

[0002] Since the discovery of the tunneling magnetoresistance (TMR) effect in Fe / Ge / Co multilayers in 1975 and the giant magnetoresistance (GMR) effect in magnetic multilayers in 1988, great progress has been made in the research and application of physics and materials science in spin electronics. In particular, the tunneling transport properties of spin-related electrons in magnetic tunnel junctions and the tunneling magnetoresistance effect have become one of the important research areas in condensed matter physics. In 1995, Miyazaki et al. and Modorola et al. respectively discovered a high room-temperature tunneling magnetoresistance effect in "ferromagnetic metal / Al-O insulating barrier / ferromagnetic metal", which once again set off a wave of research on the magnetoresistance effect. In terms of device applications, in 1993, Johnson proposed a "ferromagnetic metal / nonmagnetic metal / ferromagnetic metal" sandwich all-metal spin transistor structure consisting of a ferromagnetic metal emitter, a nonmagnetic metal base and a ferromagnetic metal collector [see M. Johnson's article Science 260 (1993) 320]. The speed of this all-metal transistor is comparable to that of semiconductor Si devices, but the energy consumption is 10-20 times lower, the density is about 50 times higher, and it is radiation-resistant and has memory function. It can be applied to various logic circuits and processors of future quantum computers. In 1994, IBM developed a read head using the GMR effect, which increased the storage density of magnetic hard disks by 17 times to 3Gb / in. 2 At present, the magnetic read head technology based on the TMR effect has increased the storage density of magnetic hard disks to 2000Gb / in 2 above.

[0003] The traditional GMR spin valve structure adopts a sandwich structure of "magnetic layer / intermediate layer / magnetic layer", in which the magnetic layer is formed by a ferromagnetic conductive material, and the intermediate layer generally uses a non-magnetic conductive metal layer such as Cu and Ru. The current can flow vertically or in-plane through the GMR spin valve structure, and the parallel and anti-parallel configuration of the magnetic moments of the two magnetic layers is used to generate magnetoresistance. It has been determined that magnetoresistance is an interface effect, which mainly uses the polarization and scattering of electrons at the interface between the magnetic layer and the intermediate layer to generate spin-polarized current, and then uses the parallel and anti-parallel configuration of the magnetic moments of the two magnetic layers to regulate the transport of spin-polarized current, thereby generating magnetoresistance. However, for the current bulk structure GMR spin valve device, when electrons flow in the upper and lower magnetic layers and the middle conductive spacer layer, they will not only be subject to a certain degree of spin scattering, but also a considerable part of the spin-polarized current will be shunted in the upper and lower magnetic layers, which will significantly reduce the size of the magnetoresistance of the GMR spin valve structure and increase the background noise.

[0004] It can be seen that the traditional GMR giant magnetoresistance device still has many shortcomings, which limits its practical application range. Therefore, it is necessary to continue to explore new spin devices to overcome the above or other shortcomings in the prior art. Summary of the invention

[0005] In order to fundamentally solve this problem, we can also consider using other carriers of spin information, such as spin waves or their quantized units - magnetic excitons (also called magnetic oscillators, or magnons for short) to transmit angular momentum information, which can bring revolutionary changes to the development of low-power computer technology with both particle and wave characteristics.

[0006] An exemplary embodiment provides a planar magnetic subvalve based on gate voltage regulation, comprising: a first metal gate layer; a first ferromagnetic insulating layer arranged on the first metal gate layer; a non-magnetic conductive intermediate layer arranged on the first ferromagnetic insulating layer; a second ferromagnetic insulating layer arranged on the intermediate layer; and a second metal gate layer arranged on the second ferromagnetic insulating layer.

[0007] In one example, the intermediate layer includes a non-magnetic metal material, an organic conductor material, a semiconductor material, a two-dimensional material, or a superconducting material.

[0008] In one example, the non-magnetic metal material includes one of Au, Pt, Cu, Al, or a combination thereof.

[0009] In one example, the two-dimensional material includes AgBr, As, AuBr, AuSe, Bi, Bi2Se3, Bi2Te3, BN, C, CaI2, CdBr2, CdI2, Cu2Te, CuBr, CuI, CuTe, FeS, GaGeTe, GaS, GaSe, GaTe, GeI2, GeS, GeSe, Hf3Te2, HfS2, HfSe2, HfTe2, HgI2, In2Se3, InSe, LaI2, MgBr2, MgI2, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe 2. One or a combination of NdI2, OLuI, PbI2, PbO, PbTe, PdS2, PtO2, PtS2, PtSe2, ReSe2, Sb, Sb2Te3, SiTe2, SnO, SnS2, SnSe2, SnTe, SrI2, TaS2, TaSe2, TiBr2, TiNI, TiS2, TiSe2, TiTe2, Tl2O, Tl2S, TlF, W2N3, WS2, WSe2, WTe2, YbI2, ZnBr2, ZnI2, ZrBr, ZrI2, ZrS2, ZrSe2, and ZrTe2.

[0010] In one example, each of the first ferromagnetic insulating layer and the second ferromagnetic insulating layer includes one or more of the following materials: R3Fe5O 12 、MFe2O4、Fe3O4、BaFe 12 O 19 、SrFe 12 O 19 , and their doped compounds, wherein R is Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, and M is Mn, Zn, Cu, Ni, Mg or Co.

[0011] In one example, the first ferromagnetic insulating layer is a reference magnetic layer having a fixed magnetization direction, and the second ferromagnetic insulating layer is a free magnetic layer whose magnetization direction changes with an external magnetic field.

[0012] In one example, the intermediate layer is used to apply an in-plane current to generate a spin-polarized current at an interface between the intermediate layer and the first ferromagnetic insulating layer and at an interface between the intermediate layer and the second ferromagnetic insulating layer. The first metal gate layer and the second metal gate layer are used to receive a constant voltage or an alternating voltage to control the conversion efficiency of the spin-polarized current into a magnon current, thereby controlling the resistance of the planar magnon valve.

[0013] Another exemplary embodiment provides an electronic device, comprising the planar magnetic subvalve based on gate voltage regulation.

[0014] In one example, the electronic device is a magnetic sensor or a temperature sensor.

[0015] The above and other features and advantages of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A Schematic diagram of the layer structure of a planar magnetic subvalve based on gate voltage regulation under zero magnetic field according to an exemplary embodiment of the present invention.

[0017] Figure 1B Schematic diagram of the layer structure of a planar magnetic subvalve under a strong magnetic field based on gate voltage regulation according to an exemplary embodiment of the present invention.

[0018] Figure 2A It is a schematic diagram when the first and second ferromagnetic layers are in a parallel state, the magnetic moment direction of the first ferromagnetic layer is the same as the spin direction of the middle layer, and the magnetic moment direction of the second ferromagnetic layer is opposite to the spin direction of the middle layer.

[0019] Figure 2B It is a schematic diagram when the first and second ferromagnetic layers are in a parallel state, the magnetic moment direction of the first ferromagnetic layer is opposite to the spin direction of the middle layer, and the magnetic moment direction of the second ferromagnetic layer is the same as the spin direction of the middle layer.

[0020] Figure 2C It is a schematic diagram when the first and second ferromagnetic layers are in an antiparallel state, the magnetic moment direction of the first ferromagnetic layer is opposite to the spin direction of the middle layer, and the magnetic moment direction of the second ferromagnetic layer is opposite to the spin direction of the middle layer.

[0021] Figure 2D It is a schematic diagram when the first and second ferromagnetic layers are in a parallel state, the magnetic moment direction of the first ferromagnetic layer is the same as the spin direction of the middle layer, and the magnetic moment direction of the second ferromagnetic layer is the same as the spin direction of the middle layer. DETAILED DESCRIPTION

[0022] Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the accompanying drawings may not be drawn to scale.

[0023] Figure 1A and Figure 1B1 is a schematic diagram of the layer structure of a planar magnetic subvalve 100 based on gate voltage regulation in zero magnetic field and strong magnetic field according to an exemplary embodiment of the present invention. As shown in FIG1 , the planar magnetic subvalve device 100 includes a first metal gate layer 110, a first ferromagnetic insulating layer 120, a non-magnetic conductive intermediate layer 130, a second ferromagnetic insulating layer 140 and a third metal gate layer 150.

[0024] The first ferromagnetic insulating layer 120 and the second ferromagnetic insulating layer 140 can each be formed of a ferromagnetic insulating material, examples of which include but are not limited to: R3Fe5O 12 , where R can be Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; MFe2O4, where M can be Mn, Zn, Cu, Ni, Mg, and Co; and Fe3O4, BaFe 12 O 19 、SrFe 12 O 19 The intermediate layer 130 may be formed of various non-magnetic materials capable of conducting electricity, such as non-magnetic metals, organic conductors, semiconductors, two-dimensional materials, and superconducting materials.

[0025] In some examples, the first ferromagnetic insulating layer 120 may have a fixed magnetization direction that does not change during device operation, as indicated by a solid arrow; the magnetization direction of the first ferromagnetic insulating layer 120 may be fixed by various means, such as antiferromagnetic pinning, hard magnetic pinning, artificial antiferromagnetic structure (SAF), self-pinning, etc. These methods are all known in the art and therefore will not be described in detail one by one.

[0026] The second ferromagnetic insulating layer 140 may have a free magnetization direction that can change with an external magnetic field. Figure 1A As shown, under zero magnetic field, the initial magnetization directions of the first ferromagnetic insulating layer 120 and the second ferromagnetic insulating layer 140 can be perpendicular to each other. When there is an external magnetic field, the magnetic moment of the second ferromagnetic insulating layer 140 can rotate freely with the direction of the external magnetic field, so as to sense the magnitude of the external magnetic field through the resistance state of the planar magnetic subvalve 100. Figure 1BIt is shown that the magnetization direction of the second ferromagnetic insulating layer 140 is parallel or anti-parallel to the second ferromagnetic insulating layer 120. It can be understood that when the strength of the external magnetic field exceeds an upper limit value, the magnetic moment of the second ferromagnetic insulating layer 140 reaches saturation, and the upper limit value is also called the upper limit of the range of the planar magnetic subvalve 100. It can be understood by those skilled in the art that the setting of the magnetization direction of the first ferromagnetic insulating layer 120 and the second ferromagnetic insulating layer 140 can be similar to the setting of the magnetization direction of the two ferromagnetic conductive layers in the traditional GMR spin valve structure. It can also be understood that in application scenarios such as memory, the initial magnetization directions of the first ferromagnetic insulating layer 120 and the second ferromagnetic insulating layer 140 can also be parallel or anti-parallel to each other.

[0027] Existing theories show that when a current passes through the conductive intermediate layer 130, polarized electron spins will accumulate at its upper and lower interfaces. The direction of spin accumulation is parallel or anti-parallel to the direction of the first ferromagnetic insulating layer 120, and there is excitation and annihilation of magnons at their interfaces. Under zero magnetic field, the direction of the second ferromagnetic insulating layer 130 is perpendicular to the direction of spin accumulation, and spin accumulation has a spin transfer torque effect on the magnetic moment, and spins are absorbed in large quantities. At this time, the resistance of the intermediate layer 130 is in a high resistance state. As the magnetic field increases, the magnetization direction of the second ferromagnetic insulating layer 140 gradually changes to be parallel or anti-parallel to the direction of spin accumulation, and the resistance of the intermediate layer 130 changes from a high resistance state to a low resistance state linearly with the magnetic field.

[0028] When the spin direction is opposite to the magnetic moment direction of the adjacent ferromagnetic layer 120 or 140, the ratio of polarized electron spin current converted into magnon spin current (or magnon current for short) is large, and when the directions are the same, the ratio is small. Therefore, the low resistance state is divided into four states, such as Figures 2A-2D shown.

[0029] exist Figure 2A , 2B In 2C and 2D, the arrows in the first and second ferromagnetic layers indicate the direction of the magnetic moment, the small circle and the middle black dot in the middle layer 130 indicate that the direction of the current is perpendicular to the paper surface, and the arrows indicate the spin direction of the polarized electrons.

[0030] like Figure 2A As shown, when the upper and lower magnetic layers are in a parallel state, and the direction of the magnetic moment of the first ferromagnetic layer is the same as the direction of the polarized electron spin of the middle layer, and the direction of the magnetic moment of the second ferromagnetic layer is opposite to the direction of the polarized electron spin of the middle layer, the magnetic current flowing between the first ferromagnetic layer and the middle layer is small, and the magnetic current flowing between the second ferromagnetic layer and the middle layer is large. At this time, the resistance of the planar magnetic subvalve device 100 is at an intermediate value, for example, R1.

[0031] like Figure 2BAs shown, when the upper and lower magnetic layers are in a parallel state, and the direction of the magnetic moment of the first ferromagnetic layer is opposite to the direction of the polarized electron spin of the middle layer, and the direction of the magnetic moment of the second ferromagnetic layer is the same as the direction of the polarized electron spin of the middle layer, the magnon current flowing between the first ferromagnetic layer and the middle layer is large, and the magnon current flowing between the second ferromagnetic layer and the middle layer is small. At this time, the resistance of the planar magnon valve device 100 is at an intermediate value, for example, R2.

[0032] like Figure 2C As shown, when the upper and lower magnetic layers are in an antiparallel state, and the directions of the magnetic moments of the first and second ferromagnetic layers are opposite to the directions of the polarized electron spins of the middle layer, the magnon currents flowing between the first and second ferromagnetic layers and the middle layer are large. At this time, the resistance of the planar magnon valve device 100 is at its maximum value, for example, R3.

[0033] like Figure 2D As shown, when the upper and lower magnetic layers are in an antiparallel state, and the directions of the magnetic moments of the first and second ferromagnetic layers are the same as the directions of the polarized electron spins of the middle layer, the magnon currents flowing between the first and second ferromagnetic layers and the middle layer are small. At this time, the resistance of the planar magnon valve device 100 is at a minimum value, for example, R4.

[0034] On top Figures 2A-2D In the various cases shown, when the magnon current generated by the spin electron current is large, the polarizability of the spin electron current will decrease, resulting in an increase in the resistance of the planar magnon valve device 100; when the magnon current generated by the spin electron current is small, the polarizability of the spin electron current will remain large, resulting in a small resistance of the planar magnon valve device 100. Therefore, in the case of fixing the in-plane current direction in the intermediate layer, by adjusting the magnetic moment of the free magnetic layer to be parallel or antiparallel to the magnetic moment of the reference magnetic layer and the direction of the spin polarized current generated by the current in the intermediate layer, the magnon magnetoresistance (MMR) of the planar magnon valve device 100 can be controlled, and it satisfies R3>R 1,2 >R4.

[0035] Existing theories show that applying voltage at the interface between heavy metals and magnetic insulators can change the spin mixing conductance and spin-magnon conversion efficiency at the interface.

[0036] When a voltage is applied between the first metal gate layer 110 and the third metal gate layer 150, the spin mixing conductance and spin-magnon conversion efficiency at the interface between the first / third metal gate layer 110 / 150 and the first / second ferromagnetic insulating layer 120 / 140 can be regulated, thereby changing the size of the polarized electron spin flow converted into the magnon flow, further causing a change in the resistance of the planar magnon valve device 100.

[0037] Therefore, by constructing a pair of upper and lower metal gate layers on the upper and lower ferromagnetic layers of the planar magnetic sub-valve and further applying a DC or AC gate voltage (f=0~10GHz, V=0~110V), the voltage-controlled magnetic sub-valve magnetic sensitive sensor can respond to low-frequency and high-frequency signals of external steady magnetic fields or alternating magnetic fields.

[0038] The planar magnetic subvalve device 100 shown in FIG1 can be prepared by various methods. For example, the material of the grown intermediate layer 130 can be transferred to the first ferromagnetic insulating layer 120, and then the second ferromagnetic insulating layer 140 can be laminated on the material of the intermediate layer 130, or after the first ferromagnetic insulating layer 120 is deposited in a first device such as a magnetron sputtering device, it can be transferred to a second device such as a chemical vapor deposition device (CVD) to grow the intermediate layer 130, and then transferred to the first device to continue to deposit the second ferromagnetic insulating layer 140. Of course, in addition to the magnetron sputtering device and the chemical vapor deposition device described as examples, other commonly used devices such as laser pulse deposition (PLD) or molecular beam epitaxy (MBE) or devices to be developed in the future can also be used to deposit or grow the various layers of the planar magnetic subvalve device 100.

[0039] It should be understood that the planar magnetic subvalve device 100 of the present invention can be applied to various electronic devices like traditional GMR devices. For example, by utilizing the characteristics of its MMR showing linear changes and signal output with the external magnetic field, the planar magnetic subvalve device 100 can be used as a magnetic sensor in the read head of a magnetic storage device or in a positioning or navigation device such as an electronic compass. For another example, by utilizing the characteristics of its MMR showing linear changes and signal output with temperature within a specific temperature range, the planar magnetic subvalve device 100 can be used as a temperature sensor in the field of industrial automation to monitor and control the temperature of industrial processes, or in the field of environmental monitoring to monitor indoor and outdoor temperatures and atmospheric temperatures. The structures of these electronic devices are known in the relevant field, and their detailed descriptions are omitted here. The planar magnetic subvalve device 100 can also be used in other electronic devices such as switches and modulators for the transmission of magnetic subcurrents (spin waves), which are not listed here one by one.

[0040] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A planar magnetic subvalve based on gate voltage regulation, comprising: a first metal gate layer; a first ferromagnetic insulating layer disposed on the first metal gate layer; a non-magnetic conductive intermediate layer disposed on the first ferromagnetic insulating layer; a second ferromagnetic insulating layer disposed on the intermediate layer; as well as A second metal gate layer is disposed on the second ferromagnetic insulating layer.

2. The planar magnetic subvalve according to claim 1, wherein: The intermediate layer includes non-magnetic metal material, organic conductor material, semiconductor material, two-dimensional material, or superconducting material.

3. The planar magnetic subvalve according to claim 2, wherein: The non-magnetic metal material includes one of Au, Pt, Cu, Al or a combination thereof. The two-dimensional materials include AgBr, As, AuBr, AuSe, Bi, Bi2Se3, Bi2Te3, BN, C, CaI2, CdBr2, CdI2, Cu2Te, CuBr, CuI, CuTe, FeS, GaGeTe, GaS, GaSe, GaTe, GeI2, GeS, GeSe, Hf3Te2, HfS2, HfSe2, HfTe2, HgI2, In2Se3, InSe, LaI2, MgBr2, MgI2, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, One or a combination of dI2, OLuI, PbI2, PbO, PbTe, PdS2, PtO2, PtS2, PtSe2, ReSe2, Sb, Sb2Te3, SiTe2, SnO, SnS2, SnSe2, SnTe, SrI2, TaS2, TaSe2, TiBr2, TiNI, TiS2, TiSe2, TiTe2, Tl2O, Tl2S, TlF, W2N3, WS2, WSe2, WTe2, YbI2, ZnBr2, ZnI2, ZrBr, ZrI2, ZrS2, ZrSe2, and ZrTe2.

4. The planar magnetic subvalve according to claim 1, wherein: Each of the first ferromagnetic insulating layer and the second ferromagnetic insulating layer comprises one or more of the following materials: R3Fe5O 12 、MFe2O4、Fe3O4、BaFe 12 O 19 、SrFe 12 O 19 , and their doped compounds, wherein R is Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, and M is Mn, Zn, Cu, Ni, Mg or Co.

5. The planar magnetic subvalve according to claim 1, wherein: The first ferromagnetic insulating layer is a reference magnetic layer with a fixed magnetization direction, and the second ferromagnetic insulating layer is a free magnetic layer whose magnetization direction changes with an external magnetic field.

6. The planar magnetic subvalve according to claim 1, wherein: The intermediate layer is used to apply an in-plane current to generate a spin polarized current at an interface between the intermediate layer and the first ferromagnetic insulating layer and at an interface between the intermediate layer and the second ferromagnetic insulating layer. The first metal gate layer and the second metal gate layer are used to receive a constant voltage or an alternating voltage to control the conversion efficiency of the spin polarized current into a magnon current, thereby controlling the resistance of the planar magnon valve.

7. An electronic device comprising the planar magnetic subvalve according to any one of claims 1 to 6.

8. The electronic device according to claim 7, wherein: The electronic device is a magnetic sensor or a temperature sensor.

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