Single-molecule spin memory based on dual-wavelength photoelectric effect and preparation method thereof

Abstract

The invention relates to the technical field of molecular photoelectric devices, and provides a single-molecule spin memory based on a dual-wavelength photoelectric effect and a preparation method thereof, and the memory comprises a magnetic metal organic complex, a graphene nano-gap array electrode, a magnetic tunnel junction and a heavy metal back gate. The magnetic metal organic complex has a chiral induced spin selection effect and a dual-wavelength photoelectric effect; a magnetic metal organic complex is connected to the graphene nano-gap array electrode through an amide covalent bond to form a magnetic metal organic complex heterojunction; the magnetic tunnel junctions are symmetrically arranged on two sides of the magnetic metal organic complex heterojunction; the graphene nano-gap array electrode and the magnetic metal organic complex are assembled on the top of the heavy metal back gate. According to the invention, the read-write speed of the memory is obviously improved, the power consumption is reduced, and the development of a spintronics memory with high speed, low power consumption and high stability is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular photoelectric devices, and in particular to a single-molecule spin memory based on a dual-wavelength photoelectric effect and a preparation method thereof. Background Art

[0002] Existing storage technologies, especially semiconductor memory and magnetic memory, face bottlenecks in storage density, speed, and power consumption. Magnetic memory relies on an external magnetic field during the writing process, resulting in high energy consumption and slow response speed. Semiconductor memory (such as flash memory) is prone to degradation and poor thermal stability during miniaturization, and the read and write speeds are difficult to meet the needs of large-scale data processing. Therefore, there is an urgent need for a new type of memory that can achieve high-speed and high-density data storage at low power consumption and solve the bottlenecks of existing technologies. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a single-molecule spin memory based on dual-wavelength photoelectric effect and a preparation method thereof, which greatly improves the read and write speed of the memory (to nanosecond level) and significantly reduces power consumption (to nanoampere level) by integrating multiple mechanisms such as photoelectric effect, chirality-induced spin selection effect (CISS), spin transfer torque effect (STT), spin orbit torque effect (SOT) and tunneling magnetoresistance effect (TMR), providing a new solution for the next generation of ultra-high-speed, low-power, and highly integrated spin electronics memory.

[0004] The present invention provides a single-molecule spin memory based on dual-wavelength photoelectric effect, comprising: A magnetic metal organic complex, wherein the magnetic metal organic complex has a chiral induced spin selection effect and self-assembles into two α-helical structures with opposite chirality; the magnetic metal organic complex has a dual-wavelength photoelectric effect, and different light wavelengths excite different photosensitive groups to generate photocurrent; A graphene nanogap array electrode, wherein the magnetic metal organic complex is connected to the graphene nanogap array electrode through an amide covalent bond to form a magnetic metal organic complex heterojunction; A magnetic tunnel junction, wherein the magnetic tunnel junction is symmetrically arranged on both sides of the magnetic metal-organic complex heterojunction; The heavy metal back gate, the graphene nanogap array electrode and the magnetic metal organic complex are all assembled on the top of the heavy metal back gate.

[0005] Furthermore, the structural formula of the magnetic metal organic complex is: Wherein, n is an integer of 6 to 10; m is an integer of 6 to 10; and M is any one of iron, cobalt, and nickel.

[0006] Furthermore, the magnetic tunnel junction includes a tunneling layer and a magnetic metal layer stacked in sequence, the tunneling layer includes any one of aluminum oxide, magnesium oxide or molybdenum disulfide, and the magnetic metal layer includes any one of iron, cobalt or nickel. The tunneling layer is assembled on the top of the heavy metal back gate, the tunneling layer has a thickness of 0.8~1.2 nm, and the magnetic metal layer has a thickness of 80~100 nm.

[0007] Furthermore, the heavy metal back gate includes a platinum layer, an aluminum oxide layer and a hafnium oxide layer stacked in sequence, wherein the bottom is a platinum layer with a deposition thickness of 50-80 nm, the aluminum oxide layer has a deposition thickness of 0.5-1 nm, and the top is a hafnium oxide layer with a deposition thickness of 0.5-1 nm.

[0008] Furthermore, it also includes a hexagonal boron nitride protective layer, which covers the magnetic tunnel junction, the graphene nanogap array electrode and the top of the magnetic metal organic complex heterojunction.

[0009] The present invention also provides a method for preparing a single-molecule spin memory based on a dual-wavelength photoelectric effect, which is used to prepare any of the single-molecule spin memories based on a dual-wavelength photoelectric effect described above, comprising the following steps: S1: Preparation of magnetic metal organic complexes; S2: preparing heavy metal back gate; S3: preparing a graphene nanogap array electrode, and preparing a symmetrical magnetic tunnel junction on both sides of the graphene nanogap array electrode; S4: Magnetic metal organic complexes are connected to graphene nanogap array electrodes through covalent bonds to obtain single-molecule spin memory; S5: Assemble the single-molecule spin memory just above the heavy metal back gate and prepare a hexagonal boron nitride protective layer just above the single-molecule spin memory to obtain a single-molecule spin memory based on the dual-wavelength photoelectric effect.

[0010] Further, S2 includes the following steps: S21: Depositing SiO2 on the thermally oxidized silicon wafer; S22: Platinum layer deposited on SiO2 at room temperature using DC magnetron sputtering technique; S23: depositing an aluminum oxide layer on the platinum layer at room temperature using an AC magnetron sputtering technique; S24: Depositing a top hafnium oxide layer on the aluminum oxide layer at 100° C. to 200° C. using an atomic layer deposition technique to obtain a back gate sample; S25: annealing the back gate sample to obtain a heavy metal back gate.

[0011] Furthermore, S3 includes the following steps: S31: growing a single layer of graphene on the surface of copper foil by chemical vapor deposition and transferring it to the surface of silicon wafer by means of polymethyl methacrylate; S32: using a UV lithography machine to perform the first photolithography, making a marking pattern on the graphene surface and evaporating metal Cr and Au; A second photolithography is performed using an ultraviolet photolithography machine to make a stripe pattern on the graphene surface, and then the graphene is etched in a reactive ion etcher to obtain a graphene stripe structure; A third photolithography process was performed using an ultraviolet lithography machine to make electrode patterns on the left and right sides of the graphene strip structure, and magnesium oxide and cobalt were sequentially evaporated by magnetron sputtering to obtain magnetic tunnel junctions on both sides of the graphene strip. S33: A polymethyl methacrylate protective layer is spin-coated on the surface of the graphene strip structure with magnetic tunnel junctions on both sides, and a polymethyl methacrylate dotted window parallel to the metal electrode is made using electron beam exposure technology. The graphene is broken into head-to-head triangular arrays through the polymethyl methacrylate window using a reactive ion etcher, and the graphene nanogap array electrode is obtained by electrical burning.

[0012] Further, S4 includes the following steps: S41: mixing the magnetic metal organic complex and the dehydration activator, and dissolving them in a solvent in an anhydrous and oxygen-free environment to obtain a mixed solution; S42: The device containing the graphene nanogap point electrode is sealed in a two-necked flask, and the evacuation operation is repeated, and the mixed solution is added to make the reaction in an inert gas atmosphere, and the reaction is carried out in the dark for 24 to 48 hours, and then the device is taken out, washed, and dried to obtain a single-molecule spin memory.

[0013] Further, the dehydration activator is selected from any one of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloric acid, dicyclohexylcarbodiimide or N,N'-diisopropylcarbodiimide; the solvent is selected from any one of pyridine, dimethyl sulfoxide or trichlorobenzene; the inert gas is argon or nitrogen; the molar ratio of the magnetic metal organic complex to the dehydration activator is 1:(20-40); the concentration of the dehydration activator is 2×10 -3 ~ 4×10 -3 mol / L.

[0014] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention provides a single-molecule spin memory based on dual-wavelength photoelectric effect and a preparation method thereof, which provides an efficient spin storage solution by combining photoelectric effect, chiral induced spin selection effect (CISS), spin transfer torque effect (STT) and spin orbit torque effect (SOT). Without using polarized light, the photosensitive group in the molecule is directly excited by the dual-wavelength photoelectric effect, and the generated photocurrent is converted into spin polarized current by the chiral spin selection effect (CISS). After flowing through the chiral helical polypeptide, different chiral structures generate currents with different spin directions, realizing precise spin control. Further utilizing the STT effect, magnetic metal atoms are injected to induce spin flipping for information writing. In addition, the SOT effect reduces the breakdown risk of the magnetic tunnel junction by separating the write path from the read path, significantly improves the read and write speed (nanosecond level) and reduces the power consumption (nanoampere level). The comprehensive application of this series of technologies has promoted the development of high-speed, low-power and high-stability spin electronics memory.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The schematic diagram is a structural diagram of a single-molecule spin memory based on dual-wavelength photoelectric effect of the present invention.

[0018] Figure 2 The present invention shows a current-bias characteristic curve before and after the connection of a single-molecule spin memory based on the dual-wavelength photoelectric effect.

[0019] Figure 3 The present invention is a schematic diagram of information reading and writing of a single-molecule spin memory based on a dual-wavelength photoelectric effect when no gate voltage is applied.

[0020] Figure 4 The present invention is a schematic diagram of information reading and writing when gate voltage is applied in a single-molecule spin memory based on the dual-wavelength photoelectric effect.

[0021] Figure 5 A single-molecule spin memory based on dual-wavelength photoelectric effect of the present invention R -Peptide synthesis roadmap.

[0022] Figure 6 A single-molecule spin memory based on dual-wavelength photoelectric effect of the present invention S -Peptide synthesis roadmap.

[0023] Reference numerals: 101. Silicon wafer; 102. SiO2 layer; 103. Platinum layer; 104. Aluminum oxide layer; 105. Hafnium oxide layer; 106. Tunneling layer; 107. Magnetic metal layer; 108. Graphene nanogap array electrode; 109. Magnetic metal organic complex; 110. Hexagonal boron nitride protective layer. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0025] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0026] Combine the following Figures 1 to 6 The invention describes a single-molecule spin memory based on dual-wavelength photoelectric effect and a preparation method thereof.

[0027] like Figure 1 As shown, a single-molecule spin memory based on the dual-wavelength photoelectric effect, A single-molecule spin memory based on dual-wavelength photoelectric effect, comprising: a magnetic metal organic complex 109, a graphene nanogap array electrode 108, a magnetic tunnel junction and a heavy metal back gate; The magnetic metal organic complex has a chirality-induced spin selection effect and self-assembles into two α-helical structures with opposite chirality; the magnetic metal organic complex has a dual-wavelength photoelectric effect, and different light wavelengths excite different photosensitive groups to generate photocurrent; the magnetic metal organic complex is connected to the graphene nanogap array electrode through an amide covalent bond to form a magnetic metal organic complex heterojunction; The magnetic tunnel junction is symmetrically arranged on both sides of the magnetic metal-organic complex heterojunction; The graphene nanogap array electrode 108, the magnetic metal organic complex 109 and the magnetic tunnel junction are all assembled on top of the heavy metal back gate.

[0028] The structural formula of the magnetic metal organic complex is: Wherein, n is an integer of 6 to 10; m is an integer of 6 to 10; and M is any one of iron, cobalt, and nickel.

[0029] The magnetic metal organic complex is any one of A1 to A3.

[0030] The structural formula of A1 is: The structural formula of A2 is: The structural formula of A3 is: The magnetic tunnel junction includes a tunneling layer 106 and a magnetic metal layer 107 stacked in sequence, wherein the tunneling layer 106 includes any one of aluminum oxide, magnesium oxide or molybdenum disulfide, and only allows electrons to pass through in a tunneling manner, thereby improving the efficiency of spin-polarized current injection; the magnetic metal layer 107 includes any one of iron, cobalt or nickel metals, and the spin-up and spin-down electronic states of these materials are unevenly distributed near the Fermi level, thereby generating a net magnetic moment, which serves as a magnetic layer; when the magnetization directions of the magnetic layer and the magnetic metal-organic complex are parallel to each other, the tunneling probability of electrons from one magnetic layer to another is high, and the information is recorded as "1" at this time; and when the magnetization directions of the magnetic layer and the magnetic metal-organic complex become anti-parallel, the tunneling probability is low, so the resistance increases, and the information is recorded as "0" at this time.

[0031] The tunneling layer is assembled on the top of the heavy metal back gate, the thickness of the tunneling layer is 0.8-1.2 nm, and the thickness of the magnetic metal layer is 80-100 nm.

[0032] Magnetic tunnel junction and magnetic metal-organic heterojunction together constitute the basic structure of tunneling magnetoresistance (TMR) effect.

[0033] The heavy metal back gate includes a platinum layer 103, an aluminum oxide layer 104 and a hafnium oxide layer 105 stacked in sequence, wherein the bottom is a platinum (Pt) layer with a deposition thickness of 50~80 nm, the aluminum oxide (Al2O3) layer has a deposition thickness of 0.5~1 nm, and the top is a hafnium oxide (HfO2) layer with a deposition thickness of 0.5~1 nm.

[0034] SiO 2 is deposited on the silicon wafer 101 , and a heavy metal back gate is deposited on the SiO 2 layer 102 .

[0035] In some specific embodiments of the present invention, when current is passed along the heavy metal, a spin-orbit moment SOT is generated to induce magnetization reversal of the molecule directly above it, which serves as an auxiliary means for magnetization reversal of the polypeptide helical spin polarized current STT, without the need for external magnetic and electric fields. This writing method eliminates the initial delay and increases the writing speed. Moreover, due to the assistance of the spin Hall effect, there is no need for current to flow through the magnetic tunnel junction, thus avoiding barrier breakdown.

[0036] The top view of the heavy metal back gate Pt / Al2O3 / HfO2 is a rectangle with a length and width of 2 mm×0.02 mm, and is located directly below the molecular heterojunction.

[0037] The graphene nanogap array electrode used in the present invention matches the size of the magnetic metal organic complex with dual-wavelength photoelectric effect, and has a carboxyl terminal, which can form a stable amide bond with the amino terminal of the magnetic metal organic complex through an amide condensation reaction, thereby increasing the charge transfer speed, thereby increasing the operating speed and stability of the device, and enabling the device to switch sensitively and quickly between high and low conductivity states.

[0038] The graphene nanogap array electrode has a thickness of 0.5-2 nm and a gap distance of 2-20 nm, and is located directly above the heavy metal back gate. The magnetic metal-organic complex heterojunction with dual-wavelength photoelectric effect has a thickness of 0.5-2 nm and is located directly above the heavy metal back gate.

[0039] Switching the wavelength of light can cause the magnetic metal organic complex to quickly switch its high and low conductivity states, representing binary data "0" and "1" respectively, serving as a carrier of information.

[0040] Among them, different light wavelengths can excite different photosensitive groups to generate photocurrents. 351 nm excites ECz photosensitive groups to generate photocurrents, and 459 nm excites Ru photosensitive groups to generate reverse photocurrents. When switching the light wavelength, current is injected into α-helices of different chirality from both sides. According to the CISS effect, spin-polarized currents with different spin directions are generated. According to the STT effect, the magnetic metal atoms in the center of the molecule are magnetized in different directions, and show high and low conductivity states under the TMR effect, realizing the writing of information. Therefore, changing the light wavelength can realize the switching between "0" and "1".

[0041] It also includes a hexagonal boron nitride protective layer 110. The hexagonal boron nitride (h-BN) protective layer covers the magnetic tunnel junction, the graphene nanogap array electrode, and the top of the magnetic metal organic complex heterojunction. On the one hand, the van der Waals contact is used to suppress the molecular conformation disturbance and reduce the electrical noise; on the other hand, it isolates the external electromagnetic interference and the air effect, thereby improving the storage stability and anti-interference ability of the device.

[0042] The single-molecule spin memory based on the dual-wavelength photoelectric effect provides a new information storage and processing solution by integrating multiple mechanisms such as the photoelectric effect, chirality-induced spin selection effect (CISS), spin transfer torque effect (STT), spin-orbit torque effect (SOT), and tunneling magnetoresistance effect (TMR). First, the introduction of the dual-wavelength photoelectric effect allows the switching of the current direction to be precisely controlled by selecting different wavelengths of light; then, CISS uses the chirality difference of helical polypeptides to generate polarized currents with different spin directions; further, the magnetic metal atoms are injected through STT to induce spin flipping, thereby achieving an efficient writing process; on the other hand, using TMR, the magnetic electrodes on both sides can read the conductivity state of the magnetic metal atoms in two magnetization directions with a weak current; at the same time, SOT can separate the writing path from the reading path by assisting the magnetization flipping of the magnetic metal atoms through the heavy metal back gate, avoiding the breakdown of the magnetic tunnel junction, thereby improving the reliability and read-write speed of the storage device. Through the combined use of these technologies, the read and write speed of the memory has been greatly improved (to nanoseconds), and the power consumption has been significantly reduced (to nanoamperes), providing a new solution for the next generation of ultra-high-speed, low-power, and highly integrated spin electronics memory.

[0043] A method for preparing a single-molecule spin memory based on a dual-wavelength photoelectric effect, which is used to prepare a single-molecule spin memory based on a dual-wavelength photoelectric effect, comprises the following steps: S1: Preparation of magnetic metal organic complexes; S11: Preparation R - polypeptide (molecule 1), R -The structural formula of the polypeptide is: Synthesis route such as Figure 5 As shown, R-The synthesis of peptides adopts the standard Fmoc protection solid phase synthesis method (SPPS), and the specific steps are as follows: First, Wang resin is swollen in N, N-dimethylformamide (DMF) for 15 min to fully expose the reaction site, and then 30% piperidine + 70% DMF (volume ratio) solution is added, and the Fmoc protecting group is removed. The resin is blue-purple when detected by ninhydrin, indicating that the deprotection is successful. Add 4 times the molar equivalent of the resin R-configuration amino acid, HATU (peptide condensation reagent) and 6 times the molar equivalent of the resin N, N-diisopropylethylamine (DIEA), after oscillating for 1 h, the resin is washed with DMF, CH3OH and CH2Cl2, and the resin is light yellow when detected by ninhydrin, indicating that the amino acid condensation is successful. After removing the Fmoc protecting group again with 30% piperidine + 70% DMF (volume ratio) solution, add amino acid, HATU and DIEA to carry out the coupling reaction of the next amino acid, and repeat the operation until all amino acids are connected. Finally, 95% TFA + 2.5% TIPS + 2.5% H2O (volume ratio) was added as a cutting agent and reacted with the resin for 3 hours to separate the polypeptide from the resin. The cutting liquid was collected by filtration and concentrated using a rotary evaporator. Then, -20°C ether was added to precipitate. The precipitate was collected by centrifugation to obtain a crude polypeptide product. Purification was performed using preparative reverse-phase high-performance liquid chromatography (HPLC) (C18, 10 μm, 150 Å, 30 × 150 mm) equipped with a Durashell C18 separation column. The mobile phase gradient was set from "5% acetonitrile + 95% water" (volume ratio) to "95% acetonitrile + 5% water" (volume ratio) at a flow rate of 10 mL / min. The filtrate corresponding to the target absorption peak was collected and freeze-dried to obtain R -Peptides.

[0044] 1 H NMR (400 MHz, Chloroform- d ) δ 9.56 (s, 1H), 7.47 (d, J = 8.6 Hz,1H), 7.37 (d, J = 8.0 Hz, 5H), 7.18 (d, J = 7.7 Hz, 1H), 4.32 – 4.19 (m, 7H), 3.65 (p, J = 5.8 Hz, 1H), 2.92 (dd, J = 7.9, 5.4 Hz, 1H), 2.66 (dd, J= 8.0, 5.4Hz, 1H), 1.75 – 1.47 (m, 24H), 0.94 (d, J = 6.9 Hz, 3H), 0.92 – 0.86 (m, 24H), 0.86 – 0.80 (m, 21H).

[0045] 13 C NMR (100 MHz, Chloroform- d ) δ 175.43, 174.78, 173.22, 173.17,173.16, 173.11, 173.06, 173.00, 52.76, 52.70, 52.63, 52.57, 52.51, 52.21,51.71, 51.61, 41.93, 41.61, 40.76, 40.07, 40.03, 39.98, 39.94, 39.92, 25.01,24.56, 24.53, 24.51, 24.49, 24.47, 24.44, 24.41, 22.53, 22.52, 22.51, 22.50,22.49, 22.47, 22.46, 22.45, 22.44, 22.42, 22.41, 22.40, 22.36, 22.35.

[0046] S12: Prepared in the same way S - polypeptide (molecule 2), S -The structural formula of the polypeptide is: S -Peptide synthesis routes such as Figure 6 As shown, S-The synthesis of the peptide was carried out by the standard Fmoc protection solid phase synthesis method (SPPS), and the specific steps are as follows: First, Wang resin was swollen in DMF for 15 min to fully expose the reaction site, and then 30% piperidine + 70% DMF (volume ratio) solution was added, and the Fmoc protecting group was removed. The resin was blue-purple when detected by ninhydrin, indicating that the deprotection was successful. R-configuration amino acids, HATU and DIEA were added in an amount 4 times the molar equivalent of the resin, and 6 times the molar equivalent of the resin were added. After oscillating for 1 h, the resin was washed with DMF, CH3OH and CH2Cl2. The resin was light yellow when detected by ninhydrin, indicating that the amino acid condensation was successful. After removing the Fmoc protecting group again with 30% piperidine + 70% DMF (volume ratio) solution, amino acids, HATU and DIEA were added to carry out the coupling reaction of the next amino acid, and the operation was repeated until all amino acids were connected. Finally, 95% trifluoroacetic acid (TFA) + 2.5% triisopropylsiloxy (TIPS) + 2.5% H2O (volume ratio) was added as a cutting agent and reacted with the resin for 3 hours to separate the polypeptide from the resin. The cutting liquid was collected by filtration and concentrated using a rotary evaporator. Then, -20°C ether was added to precipitate. The precipitate was collected by centrifugation to obtain a crude polypeptide product. Purification was performed using a preparative reverse-phase HPLC (C18, 10μm, 150Å, 30×150mm) equipped with a Durashell C18 separation column. The mobile phase gradient was set from "5% acetonitrile + 95% water" (volume ratio) to "95% acetonitrile + 5% water" (volume ratio) at a flow rate of 10 mL / min. The filtrate corresponding to the target absorption peak was collected and freeze-dried to obtain S -Peptides.

[0047] 1 H NMR (400 MHz, Chloroform- d ) δ 9.56 (s, 1H), 7.47 (d, J = 8.6 Hz,1H), 7.37 (d, J = 8.0 Hz, 5H), 7.18 (d, J = 7.7 Hz, 1H), 4.32 – 4.19 (m, 7H), 3.65 (p, J = 5.8 Hz, 1H), 2.92 (dd, J = 7.9, 5.4 Hz, 1H), 2.66 (dd, J = 8.0, 5.4Hz, 1H), 1.75 – 1.47 (m, 24H), 0.94 (d, J= 6.9 Hz, 3H), 0.92 – 0.86 (m, 24H), 0.86 – 0.80 (m, 21H).

[0048] 13 C NMR (100 MHz, Chloroform- d ) δ 175.43, 174.78, 173.22, 173.17,173.16, 173.11, 173.06, 173.00, 52.76, 52.70, 52.63, 52.57, 52.51, 52.21,51.71, 51.61, 41.93, 41.61, 40.76, 40.07, 40.03, 39.98, 39.94, 39.92, 25.01,24.56, 24.53, 24.51, 24.49, 24.47, 24.44, 24.41, 22.53, 22.52, 22.51, 22.50,22.49, 22.47, 22.46, 22.45, 22.44, 22.42, 22.41, 22.40, 22.36, 22.35.

[0049] S13: preparing molecules 4 that can be excited by short-wavelength light; C 18 H 15 A solution of F3N2O3 (molecule 3) (1.0 mmol), EDCI (1.1 mmol), and DMAP (0.1 mmol) in DCM (5 mL) was stirred at room temperature for 15 min, and then a solution of molecule 1 (1.0 mmol) in DCM (1 mL) was slowly added. The reaction mixture was stirred at room temperature for 12 h. The reaction was quenched with water, then extracted with DCM, washed with sodium bicarbonate aqueous solution, and the organic phases were combined, dried, and concentrated, and then purified by column chromatography to obtain molecule 4 that can be excited by short-wavelength light.

[0050] 1 H NMR (400 MHz, Chloroform- d ) δ 9.56 (s, 1H), 9.21 (d, J = 10.8 Hz,1H), 8.20 (d, J = 2.2 Hz, 1H), 8.15 (dd, J = 7.9, 1.0 Hz, 1H), 7.54 (d, J= 7.9 Hz,1H), 7.47 (dd, J = 8.5, 1.2 Hz, 2H), 7.39 – 7.34 (m, 8H), 7.33 – 7.24 (m, 2H), 5.58 (d, J = 10.8 Hz, 1H), 4.36 (q, J = 5.2 Hz, 2H), 4.33 – 4.20 (m, 8H), 1.72 –1.48 (m, 24H), 1.38 (t, J = 5.2 Hz, 3H), 0.92 – 0.87 (m, 24H), 0.86 – 0.80 (m, 24H).

[0051] 13 C NMR (100 MHz, Chloroform- d ) δ175.43, 173.23, 173.17, 173.16,173.11, 173.07, 173.06, 173.00, 172.30, 141.44, 138.63, 130.13, 126.66,125.25, 123.56, 122.76, 122.14, 120.05, 119.52, 114.89, 110.05, 56.96, 56.94,52.83, 52.76, 52.70, 52.63, 52.57, 52.21, 52.03, 51.61, 40.76, 36, 22.49, 22.47,22.46, 22.45, 22.44, 22.42, 22.41, 22.40, 22.36, 22.35, 13.36.

[0052] S14: Preparation of molecules 7 that can be excited by long-wavelength light; First, according to the synthesis method of molecule 4, molecule 2 and molecule 5 are used to prepare ligand molecule 6 of molecule 7; 1H NMR (400 MHz, Chloroform- d ) δ 9.56 (s, 1H), 9.13 (d, J = 10.8 Hz,1H), 8.67 (d, J = 4.3 Hz, 1H), 8.64 (dd, J = 4.1, 1.7 Hz, 1H), 8.26 (dd, J = 8.3,1.3 Hz, 1H), 8.05 (d, J = 2.4 Hz, 1H), 7.77 (ddd, J = 8.7, 7.2, 1.7 Hz, 1H), 7.54(d, J = 7.9 Hz, 1H), 7.49 – 7.45 (m, 2H), 7.37 (d, J = 8.2 Hz, 6H), 7.27 (ddd, J =7.1, 4.0, 1.3 Hz, 1H), 5.64 (d, J = 10.8 Hz, 1H), 4.34 – 4.22 (m, 7H), 4.18(dt, J = 8.7, 7.0 Hz, 1H), 1.74 – 1.45 (m, 24H), 0.91 – 0.87 (m, 24H), 0.86 –0.81 (m, 24H)。

[0053] 13 C NMR (100 MHz, Chloroform- d) δ 175.43, 173.23, 173.17, 173.16,173.11, 173.07, 173.06, 173.00, 172.32, 156.22, 155.36, 149.54, 149.35,141.51, 138.07, 123.68, 122.27, 122.04, 121.23, 57.04, 57.03, 52.83, 52.76,52.70, 52.63, 52.57, 52.21, 52.03, 51.61, 40.76, 40.36, 40.11, 22.44, 22.42, 22.41, 22.40, 22.36, 22.35.

[0054] Subsequently, molecule 7 was prepared; Under nitrogen atmosphere, a dichloromethane (DCM) solution (10 mL) of molecule 6 (1.0 mmol), Ru(bpy)2Cl2·2H2O (1.1 mmol), and NH4PF6 (10.0 mmol) was refluxed at 85°C for 3.5 h. After the reaction was completed, the solution was removed and purified by column chromatography to obtain molecule 7.

[0055] 1 H NMR (400 MHz, Chloroform- d ) δ 9.56 (s, 1H), 9.12 (d, J = 10.8 Hz,1H), 8.31 – 8.19 (m, 6H), 7.71 (ddd, J = 9.2, 7.2, 1.8 Hz, 6H), 7.54 (d, J = 7.9Hz, 1H), 7.47 (d, J = 8.6 Hz, 1H), 7.41 – 7.31 (m, 11H), 7.28 – 7.15 (m, 6H), 5.60 (d, J= 10.6 Hz, 1H), 4.34 – 4.11 (m, 8H), 1.73 – 1.48 (m, 24H), 0.92 –0.87 (m, 24H), 0.86 – 0.78 (m, 24H).

[0056] 13 C NMR (100 MHz, Chloroform- d ) δ173.33, 149.60, 148.99, 148.96,148.67, 129.84, 129.81, 126.19, 124.50, 123.65, 123.04, 122.14, 56.60, 52.37,52.35, 51.88, 51.61, 41.27, 40.46, 39.97, 39.94, 24.37, 24.30, 22.43, 22.37.

[0057] S15: Preparation of molecule 10 with amino protecting group using metal M-porphyrin complex 8 and different photoresponsive groups (molecule 4 and molecule 7); First, according to the synthesis method of molecule 4, molecule 9 is prepared using metal M-porphyrin complex 8 and molecule 4; 1 H NMR (400 MHz, Chloroform- d ) δ 9.43 (s, 1H), 9.21 (d, J = 10.8 Hz,1H), 8.20 (d, J = 2.2 Hz, 1H), 8.15 (dd, J = 7.9, 1.0 Hz, 1H), 7.62 – 7.59 (m,2H), 7.54 (d, J = 7.9 Hz, 1H), 7.52 – 7.41 (m, 9H), 7.39 – 7.33 (m, 8H), 7.32 –7.22 (m, 3H), 7.18 (d, J = 7.9 Hz, 1H), 7.13 – 7.00 (m, 7H), 6.82 – 6.78 (m,2H), 5.58 (d, J = 10.8 Hz, 1H), 4.36 (q, J = 5.2 Hz, 2H), 4.29 (dtdd,J = 13.0,6.6, 3.4, 1.8 Hz, 8H), 4.21 (d, J = 5.6 Hz, 1H), 4.13 (d, J = 5.6 Hz, 1H), 1.75 –1.51 (m, 22H), 1.38 (t, J = 5.2 Hz, 3H), 0.92 – 0.86 (m, 24H), 0.85 – 0.81 (m, 24H).

[0058] 13 C NMR (100 MHz, Chloroform- d ) δ 173.33, 130.95, 130.59, 126.16,125.91, 125.83, 125.52, 125.09, 125.03, 121.44, 119.64, 119.52, 118.64,118.16, 115.31, 115.10, 114.57, 113.82, 112.88, 111.21, 110.13, 109.22,57.57, 52.87, 52.37, 51.61, 40.48, 40.46, 39.94, 37.94, 24.53, 24.37, 22.43,13.33.

[0059] According to the same method, molecule 9 and molecule 7 are used to prepare molecule 10 having an amino protecting group; 1 H NMR (400 MHz, Chloroform- d ) δ 9.43 (s, 2H), 9.21 (d, J = 10.8 Hz,1H), 9.12 (d, J = 10.8 Hz, 1H), 8.32 – 8.11 (m, 8H), 7.71 (ddd, J = 9.2, 7.1, 1.9Hz, 6H), 7.64 – 7.58 (m, 4H), 7.54 (d, J= 7.9 Hz, 2H), 7.52 – 7.46 (m, 6H), 7.43 – 7.39 (m, 4H), 7.39 – 7.32 (m, 19H), 7.32 – 6.99 (m, 18H), 5.64 – 5.53(m, 2H), 4.36 (q, J = 5.2 Hz, 2H), 4.33 – 4.24 (m, 16H), 1.75 – 1.52 (m, 49H), 1.38 (t, J = 5.2 Hz, 3H), 0.91 – 0.86 (m, 48H), 0.86 – 0.79 (m, 48H).

[0060] 13 C NMR (100 MHz, Chloroform- d ) δ 173.33, 148.99, 148.67, 130.59,130.41, 129.84, 126.19, 123.04, 118.68, 118.64, 52.37, 51.61, 40.48, 40.46,39.95, 24.53, 24.37, 22.43, 13.33.

[0061] S16: removing the protecting groups at both ends of the amino protecting groups of molecule 10 to obtain a magnetic metal organic complex (molecule 11); Under nitrogen atmosphere, a mixed solution of 10 (1.0 mmol) and K2CO3 (2.2 mmol) in methanol and water (10 mL, V 甲醇 : V 水 =1:1) and stirred at room temperature for 8 h. After the reaction was completed, DCM was used for extraction, and the organic phases were combined, dried, and concentrated, and then pure recrystallized from petroleum ether to obtain a magnetic metal organic complex.

[0062] 1 H NMR (400 MHz, Chloroform- d ) δ 9.43 (s, 2H), 8.32 – 8.21 (m, 7H), 8.17 – 8.12 (m, 1H), 7.81 (d, J = 2.3 Hz, 1H), 7.72 (dt, J= 8.3, 1.6 Hz, 5H),7.65 – 7.58 (m, 4H), 7.54 – 7.45 (m, 6H), 7.43 – 6.99 (m, 42H), 5.08 (dt, J =16.3, 5.6 Hz, 2H), 4.33 – 4.18 (m, 20H), 1.75 – 1.51 (m, 48H), 1.38 (t, J = 5.2Hz, 3H), 0.94 – 0.86 (m, 48H), 0.85 – 0.74 (m, 48H).

[0063] 13 C NMR (100 MHz, Chloroform- d ) δ 173.33, 148.99, 148.67, 130.59,130.41, 129.84, 126.19, 123.04, 118.68, 118.64, 52.37, 51.93, 40.48, 40.44,39.95, 24.53, 24.37, 22.43, 13.33.

[0064] S2: preparing heavy metal back gate; S21: Depositing SiO2 on a thermally oxidized silicon wafer; wherein the size of the silicon wafer is 10 mm×10 mm, and the thickness of the SiO2 layer is 300 nm; S22: Platinum layer was deposited on SiO2 at room temperature using DC magnetron sputtering technology; the length and width of the platinum layer were 2 mm × 0.02 mm and the thickness was 50~80 nm; S23: using AC magnetron sputtering technology to deposit an aluminum oxide layer on the platinum layer at room temperature; the length and width of the aluminum oxide layer are 2 mm×0.02 mm, and the thickness is 0.5~1 nm; S24: A top hafnium oxide layer is deposited on the aluminum oxide layer at (100°C~200°C) using an atomic layer deposition technique to obtain a back gate sample; the thickness of the hafnium oxide layer is 0.5~1 nm; S25: annealing the back gate sample to obtain a heavy metal back gate; The annealing treatment is performed at 200°C for 30 minutes to enhance the bonding strength and flatness between the Pt / Al2O3 / HfO2 layers.

[0065] S3: preparing a graphene nanogap array electrode, and preparing a symmetrical magnetic tunnel junction on both sides of the graphene nanogap array electrode; S31: Growing a single layer of graphene on the surface of copper foil by chemical vapor deposition and transferring it to the surface of silicon wafer with the help of polymethyl methacrylate (PMMA); S32: using a UV lithography machine to perform the first photolithography, making a marking pattern on the graphene surface and evaporating metal Cr and Au; A second photolithography was performed using an ultraviolet lithography machine to make a stripe pattern on the graphene surface, and then the surface was etched in a reactive ion etcher to obtain a graphene stripe structure; the size of the graphene stripe structure was 2.15 mm × 0.03 mm; The third photolithography was performed using an ultraviolet photolithography machine to make electrode patterns on the left and right sides of the graphene strip, and magnesium oxide and cobalt were sequentially evaporated by magnetron sputtering to obtain magnetic tunnel junctions on both sides of the graphene strip; the thickness of magnesium oxide was 0.8 nm and the thickness of cobalt was 80 nm.

[0066] S33: A PMMA protective layer was spin-coated on the surface of the graphene strip structure with magnetic tunnel junctions on both sides, and a PMMA dotted window parallel to the metal electrode was made using electron beam lithography (EBL). The size of each PMMA dotted window was 150 nm×5 nm. The graphene was broken into head-to-head triangular arrays through the PMMA window using a reactive ion etcher (RIE), and the graphene nanogap array electrode was obtained by electrical burning.

[0067] S4: Magnetic metal organic complexes are connected to graphene nanogap array electrodes through covalent bonds to obtain single-molecule spin memory; S41: mixing the magnetic metal organic complex and the dehydration activator, and dissolving them in a solvent in an anhydrous and oxygen-free environment to obtain a mixed solution; S42: sealing the device containing the graphene nanogap point electrode in a two-necked flask, repeatedly performing the pumping and ventilation operation, adding the mixed solution, making the reaction in an inert gas atmosphere, reacting for 24 to 48 hours under dark conditions, taking out, washing, and drying to obtain a single-molecule spin memory; The dehydration activator is selected from any one of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloric acid, dicyclohexylcarbodiimide or N,N'-diisopropylcarbodiimide; the solvent is selected from any one of pyridine, dimethyl sulfoxide or trichlorobenzene; the inert gas is argon or nitrogen; the molar ratio of the magnetic metal organic complex to the dehydration activator is 1:(20-40); the concentration of the dehydration activator is 2×10 -3 ~ 4×10 -3 mol / L.

[0068] S5: Assemble the single-molecule spin memory just above the heavy metal back gate and prepare a hexagonal boron nitride protective layer just above the single-molecule spin memory to obtain a single-molecule spin memory based on the dual-wavelength photoelectric effect.

[0069] In some embodiments of the present invention, the 1H and 13CNMR spectra of the compounds were recorded on Variance Mercury plus 300MHz and Bruker ARX500NMR spectrometers; all chemical shifts of 1H were referenced to tetramethylsilane (TMS, δ = 0.00ppm) or deuterated chloroform (Chloroform-d, CDCl3, δ = 7.26ppm), and 13C NMR chemical shifts were referenced to CDCl3 (δ = 77.00ppm). Mass spectra were recorded on a Bruker APEX IV mass spectrometer.

[0070] Electrical tests were performed under vacuum conditions (<1×10 -4 Pa).

[0071] Test instruments: semiconductor parameter analyzer (Keysight, B1500A), probe station (Janis Research Company, ST-500), comprehensive physical property test system (Quantum Design, PPMS DynaCool). A femtosecond laser is used to apply a light source of a specific wavelength to the device. The test temperature is precisely controlled by liquid nitrogen, liquid helium and a heating platform.

[0072] The electrical testing steps include: At any temperature between 2 K and 300 K, the source-drain voltage range is: , with an interval of 5 mV, the current-bias curve of the single-molecule spin memory before and after the connection of molecules is measured as the current changes with the bias voltage, such as Figure 2 As shown in the figure, I is the source-drain current, and V is the source-drain voltage. Before the molecules are connected, I remains at 0 nA. After the molecules are connected, the absolute value of I is greater than 5 nA at a voltage of ±1 V, and it shows nonlinear characteristics, proving that the molecules are successfully connected.

[0073] At any temperature between 2 K and 300 K, apply 50 mW (351 nm) of light to write, 0.001 V to read, 50 mW (459 nm) of light to write, 0.001 V to read, without applying gate voltage, and erase and write continuously for 100 times. Figure 3 As shown, the read and write performance of the single-molecule spin memory is stable, the read and write speed is at the level of 10~100ns, and the read and write power consumption is at the level of 0.01~1nA; Figure 3The middle figure (a) shows the writing under 50 mW (351 nm) light without gate voltage to obtain a source-drain current of 1 nA, the reading under 0.001 V without gate voltage to obtain a source-drain current of 0.02 nA, the writing under 50 mW (459 nm) light without gate voltage to obtain a source-drain current of 1 nA, the reading under 0.001 V without gate voltage to obtain a source-drain current of 0.06 nA, and the reading and writing are repeated 100 times. Figure 3 Figure (b) shows Figure 3 The curve in the range of 3000~4000ns in Figure (a) is enlarged to show the current size more clearly.

[0074] After applying an auxiliary write voltage of 0.5 V to the heavy metal gate, the above writing and reading steps are repeated again. Only 5 mW (351 nm) of light is applied to write, 0.0001 V is read, 5 mW (459 nm) of light is applied to write, 0.0001 V is read, and the erase and write is repeated 100 times continuously. Figure 4 As shown, it can be seen that the gate voltage can increase the read and write speed by an order of magnitude to the 1 ~ 10 ns level, and reduce the read and write power consumption by an order of magnitude to the 0.001 ~ 0.1 nA level. Figure 4 The middle figure (a) shows that 5 mW (351 nm) of light was applied for writing and 0.5 V of gate voltage was applied to obtain a source-drain current of 0.1 nA, 0.0001 V was applied for reading and 0.5 V of gate voltage was applied to obtain a source-drain current of 0.002 nA, 5 mW (459 nm) of light was applied for writing and 0.5 V of gate voltage was applied to obtain a source-drain current of 0.1 nA, 0.0001 V was applied for reading and 0.5 V of gate voltage was applied to obtain a source-drain current of 0.006 nA, and the reading and writing were repeated 100 times. Figure 4 Figure (b) shows Figure 4 The curve in the range of 3000 ~ 4000 ns in Figure (a) is enlarged to show the current size more clearly.

[0075] All reactions in this application were performed using standard Schlenk techniques in dry solvents and an inert atmosphere of argon.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A single-molecule spin memory based on dual-wavelength photoelectric effect, characterized in that: include: A magnetic metal organic complex, wherein the magnetic metal organic complex has a chiral induced spin selection effect and self-assembles into two α-helical structures with opposite chirality; the magnetic metal organic complex has a dual-wavelength photoelectric effect, and different light wavelengths excite different photosensitive groups to generate photocurrent; A graphene nanogap array electrode, wherein the magnetic metal organic complex is connected to the graphene nanogap array electrode through an amide covalent bond to form a magnetic metal organic complex heterojunction; A magnetic tunnel junction, wherein the magnetic tunnel junction is symmetrically arranged on both sides of the magnetic metal-organic complex heterojunction; The heavy metal back gate, the graphene nanogap array electrode and the magnetic metal organic complex are all assembled on the top of the heavy metal back gate.

2. A single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 1, characterized in that: The structural formula of the magnetic metal organic complex is: Wherein, n is an integer of 6 to 10; m is an integer of 6 to 10; and M is any one of iron, cobalt, and nickel.

3. The single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 1, characterized in that: The magnetic tunnel junction includes a tunneling layer and a magnetic metal layer stacked in sequence, the tunneling layer includes any one of aluminum oxide, magnesium oxide or molybdenum disulfide, the magnetic metal layer includes any one of iron, cobalt or nickel, the tunneling layer is assembled on the top of the heavy metal back gate, the tunneling layer has a thickness of 0.8~1.2 nm, and the magnetic metal layer has a thickness of 80~100 nm.

4. The single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 1, characterized in that: The heavy metal back gate includes a platinum layer, an aluminum oxide layer and a hafnium oxide layer stacked in sequence, wherein the bottom is a platinum layer with a deposition thickness of 50-80 nm, the aluminum oxide layer has a deposition thickness of 0.5-1 nm, and the top is a hafnium oxide layer with a deposition thickness of 0.5-1 nm.

5. The single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 1, characterized in that: It also includes a hexagonal boron nitride protective layer, which covers the magnetic tunnel junction, the graphene nanogap array electrode and the top of the magnetic metal organic complex heterojunction.

6. A method for preparing a single-molecule spin memory based on a dual-wavelength photoelectric effect, characterized in that: The method for preparing a single-molecule spin memory based on the dual-wavelength photoelectric effect as claimed in any one of claims 1 to 5 comprises the following steps: S1: Preparation of magnetic metal organic complexes; S2: preparing heavy metal back gate; S3: preparing a graphene nanogap array electrode, and preparing a symmetrical magnetic tunnel junction on both sides of the graphene nanogap array electrode; S4: Magnetic metal organic complexes are connected to graphene nanogap array electrodes through covalent bonds to obtain single-molecule spin memory; S5: Assemble the single-molecule spin memory just above the heavy metal back gate and prepare a hexagonal boron nitride protective layer just above the single-molecule spin memory to obtain a single-molecule spin memory based on the dual-wavelength photoelectric effect.

7. The method for preparing a single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 6, characterized in that: S2 includes the following steps: S21: Depositing SiO2 on the thermally oxidized silicon wafer; S22: Platinum layer deposited on SiO2 at room temperature using DC magnetron sputtering technique; S23: depositing an aluminum oxide layer on the platinum layer at room temperature using an AC magnetron sputtering technique; S24: Depositing a top hafnium oxide layer on the aluminum oxide layer at 100° C. to 200° C. using an atomic layer deposition technique to obtain a back gate sample; S25: annealing the back gate sample to obtain a heavy metal back gate.

8. The method for preparing a single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 6, characterized in that: S3 includes the following steps: S31: growing a single layer of graphene on the surface of copper foil by chemical vapor deposition and transferring it to the surface of silicon wafer by means of polymethyl methacrylate; S32: using a UV lithography machine to perform the first photolithography, making a marking pattern on the graphene surface and evaporating metal Cr and Au; A second photolithography is performed using an ultraviolet photolithography machine to produce a stripe pattern on the graphene surface, and then the graphene is etched in a reactive ion etcher to obtain a graphene stripe structure; A third photolithography process was performed using an ultraviolet lithography machine to make electrode patterns on the left and right sides of the graphene strip structure, and magnesium oxide and cobalt were sequentially evaporated by magnetron sputtering to obtain magnetic tunnel junctions on both sides of the graphene strip. S33: A polymethyl methacrylate protective layer is spin-coated on the surface of the graphene strip structure with magnetic tunnel junctions on both sides, and a polymethyl methacrylate dotted window parallel to the metal electrode is made using electron beam exposure technology. The graphene is broken into head-to-head triangular arrays through the polymethyl methacrylate window using a reactive ion etcher, and the graphene nanogap array electrode is obtained by electrical burning.

9. The method for preparing a single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 6, characterized in that: S4 includes the following steps: S41: mixing the magnetic metal organic complex and the dehydration activator, and dissolving them in a solvent in an anhydrous and oxygen-free environment to obtain a mixed solution; S42: The device containing the graphene nanogap point electrode is sealed in a two-necked flask, and the evacuation operation is repeated, and the mixed solution is added to make the reaction in an inert gas atmosphere, and the reaction is carried out in the dark for 24 to 48 hours, and then the device is taken out, washed, and dried to obtain a single-molecule spin memory.

10. The method for preparing a single-molecule spin memory based on dual-wavelength photoelectric effect according to claim 9, characterized in that: The dehydration activator is selected from any one of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloric acid, dicyclohexylcarbodiimide or N,N'-diisopropylcarbodiimide; the solvent is selected from any one of pyridine, dimethyl sulfoxide or trichlorobenzene; the inert gas is argon or nitrogen; the molar ratio of the magnetic metal organic complex to the dehydration activator is 1:(20-40); the concentration of the dehydration activator is 2×10 -3 ~ 4×10 -3 mol / L.

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