Probability bit device based on single tetra-ligand molecular dipole moment and preparation method

Abstract

The invention relates to the technical field of single molecule devices, in particular to a probability bit device based on single tetraligand molecule dipole moment and a preparation method, a single tetraligand dipole molecule is assembled between a graphene point electrode pair, the single tetraligand dipole molecule has good randomness or uncertainty characteristics, and the probability bit device can be used for preparing a probabilistic bit device based on the single tetraligand molecule dipole moment. The states of the molecules can be read through conductance, and probability bits of a single molecule scale are realized; according to the invention, the linear mapping relation between the bistable time ratio and the bias voltage parameter is established by using the voltage dependence of molecular dipole inversion, the random generation mode of the traditional probability bit is broken through, the molecular configuration dynamic state is used as the core regulation dimension, and the characteristics of high-sensitivity field response and long-time coherence are integrated. And an efficient and extensible hardware carrier is provided for quantum-classical hybrid calculation. The preparation method provided by the invention is simple in process, mild in reaction condition and beneficial to large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of single-molecule devices, and particularly to a probabilistic bit device based on the dipole moment of a single tetradentate ligand molecule and a preparation method thereof. Background Art

[0002] In traditional computing systems, the basic unit of information is the classical bit, and its binary characteristics (0 or 1) constitute the basis of deterministic computing logic. With the complication of computing requirements, quantum computing proposes quantum bits (qubits) based on quantum superposition and entanglement to achieve a breakthrough in computing power through parallelism. However, the realization of qubits is limited by the harsh requirements of the quantum environment (such as ultra-low temperature, decoherence effects, etc.), and its physical carriers (such as superconducting circuits, ion traps) often rely on complex peripheral control systems, restricting the feasibility of large-scale applications. At the same time, the concept of probabilistic bits is proposed, which simulates non-deterministic state outputs through random processes and shows unique value in the random decision-making of classical algorithms (such as Monte Carlo simulation, genetic algorithms) and quantum-classical hybrid computing. However, the realization of existing probabilistic bits mostly relies on electronic circuit random number generation or post-processing algorithms, suffering from problems such as limited randomness sources, low control freedom, and insufficient energy efficiency ratio.

[0003] In recent years, molecular devices have become a research hotspot for new computing carriers due to their unique physical and chemical properties. The multiple degrees of freedom of molecular systems (such as electronic states, configurations, dipole orientations) can provide natural randomness for information encoding, and their self-assembly ability and low energy consumption characteristics at the nanoscale have opened up new ways for high-density integration and device miniaturization. Especially in the field of dipole control, molecular systems with reversible configuration changes can achieve dipole inversion through external field driving, forming a bistable probabilistic output related to the applied bias voltage, providing a potential solution for the physical realization of probabilistic bits. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the first object of the present invention is to provide a probabilistic bit device based on the dipole moment of a single tetradentate ligand molecule; the second object of the present invention is to provide a preparation method of a probabilistic bit device based on the dipole moment of a single tetradentate ligand molecule.

[0005] To achieve the first object, the technical solution adopted by the present invention is as follows: A probabilistic bit device based on the dipole moment of a single tetradentate ligand molecule, comprising a first graphene dot electrode, a molecular bridge, and a second graphene dot electrode connected in sequence. The first graphene dot electrode and the second graphene dot electrode form a pair of graphene dot electrodes. The molecular bridge is respectively connected to the first graphene dot electrode and the second graphene dot electrode through amide bonds, and the molecular bridge serves as a functional unit for probabilistic bit control; The molecular bridge is selected from a single four-coordinate ligand dipole molecule, and the single four-coordinate ligand dipole molecule is selected from copper complexes.

[0006] Furthermore, the single four-coordinate ligand dipole molecule is selected from any one of the following structural formulas: , , .

[0007] Furthermore, the first graphene dot electrode and the second graphene dot electrode are nano-gap dot electrodes.

[0008] Furthermore, a first metal electrode and a second metal electrode are further included. The first metal electrode is evaporated on the first graphene dot electrode, and the second metal electrode is evaporated on the second graphene dot electrode. The first metal electrode and the second metal electrode form a metal electrode pair.

[0009] Furthermore, the first metal electrode and the second metal electrode are selected from gold electrodes.

[0010] Furthermore, a protective layer is further included, and the protective layer covers the metal electrode pair and the graphene dot electrode pair.

[0011] Furthermore, the protective layer is made of hexagonal boron nitride.

[0012] In order to achieve the second object, the technical solution adopted by the present invention is: A preparation method of a probabilistic bit device based on the dipole moment of a single four-coordinate ligand molecule, which is used to prepare the probabilistic bit device based on the dipole moment of a single four-coordinate ligand molecule described in any one of the above, includes the following steps: S100. Using chemical vapor deposition method and peroxide plasma etching method, prepare a single-layer graphene on a backing; S200. Using photolithography technology and peroxide ion etching technology, prepare a graphene array electrode on the single-layer graphene; S300. Using electron beam exposure etching technology, prepare a first graphene dot electrode and a second graphene dot electrode on the graphene array electrode, and perform oxygen plasma etching on the first graphene dot electrode and the second graphene dot electrode to obtain a pair of graphene nano-gap dot electrodes; S400. Place the pair of graphene nano-gap dot electrodes and a four-coordinate ligand dipole compound in a reaction system, and perform self-assembly of a single four-coordinate ligand dipole molecule and the pair of graphene nano-gap dot electrodes to obtain a probabilistic bit device based on the dipole moment of a single four-coordinate ligand molecule.

[0013] Further, in step S400, the reaction system includes a catalyst and a reaction solvent. The catalyst is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and the reaction solvent is selected from pyridine.

[0014] Further, the concentration of the tetracoordinated ligand dipole compound in the reaction system is ≥ 0.5 mM.

[0015] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention provides a probabilistic bit device based on the dipole moment of a single tetracoordinated ligand molecule and a preparation method. The probabilistic bit device assembles a single tetracoordinated ligand dipole molecule between graphene dot electrodes. The single tetracoordinated ligand dipole molecule has good randomness or uncertainty characteristics, and the state of the molecule can be read through conductance, realizing probabilistic bits at the single-molecule scale; the single tetracoordinated ligand dipole molecule is used as a molecular bridge to be connected to the first graphene dot electrode and the second graphene dot electrode through amide bonds respectively, significantly enhancing the chemical stability of the device, and thus being able to ensure the long-term reliability of the probabilistic bit device under complex operating conditions; the probabilistic bit device based on the dipole moment of a single tetracoordinated ligand molecule realizes a significant miniaturization of the device size, exhibits extremely high integration, provides new ideas for the miniaturization and high-density integration of functional chips, and lays a technical foundation for the development of future micro-nano electronics.

[0016] This application utilizes the voltage dependence of molecular dipole inversion to establish a linear mapping relationship between the bistable time ratio and the bias parameter, breaking through the randomness generation mode of traditional probabilistic bits, taking the molecular configuration dynamics as the core regulation dimension, and having both high-sensitivity field response and long-time coherence characteristics, providing an efficient and scalable hardware carrier for quantum-classical hybrid computing. Compared with the prior art, the invention has significant advantages in terms of device stability, energy efficiency ratio, and external field controllability.

[0017] The preparation method provided by the present invention has a simple process and mild reaction conditions, which is conducive to large-scale production.

[0018] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a probabilistic bit device based on the dipole moment of a single tetracoordinated ligand molecule provided by an embodiment of the present invention.

[0020] Figure 2It is the conductance high and low state swing and its time occupancy distribution of the probabilistic bit device based on the dipole moment of a single four - ligand molecule when the four - ligand dipole compound provided in Embodiment 2 of the present invention is Compound III under a bias voltage of 0.45V.

[0021] Figure 3 It is the time occupancy of the probabilistic bit device based on the dipole moment of a single four - ligand molecule when the four - ligand dipole compound provided in Embodiment 2 of the present invention is Compound III at different bias voltage high and low states.

[0022] Figure 4 It is the conductance high and low state swing and its time occupancy distribution of the probabilistic bit device based on the dipole moment of a single four - ligand molecule when the four - ligand dipole compound provided in Embodiment 2 of the present invention is Compound II under a bias voltage of 0.45V.

[0023] Figure 5 It is the time occupancy of the probabilistic bit device based on the dipole moment of a single four - ligand molecule when the four - ligand dipole compound provided in Embodiment 2 of the present invention is Compound II at different bias voltage high and low states.

[0024] Figure 6 It is the conductance high and low state swing and its time occupancy distribution of the probabilistic bit device based on the dipole moment of a single four - ligand molecule when the four - ligand dipole compound provided in Embodiment 2 of the present invention is Compound IV under a bias voltage of 0.45V.

[0025] Figure 7 It is the time occupancy of the probabilistic bit device based on the dipole moment of a single four - ligand molecule when the four - ligand dipole compound provided in Embodiment 2 of the present invention is Compound IV at different bias voltage high and low states.

[0026] Reference numerals: 11. First graphene dot electrode; 12. Second graphene dot electrode; 2. Molecular bridge; 31. First metal electrode; 32. Second metal electrode; 4. Protective layer. Detailed implementation manners

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to 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.

[0028] Such as Figure 1As shown in the figure, a probability bit device based on the dipole moment of a single four - ligand molecule includes a first graphene dot electrode 11, a molecular bridge 2, and a second graphene dot electrode 12 connected in sequence. The first graphene dot electrode 11 and the second graphene dot electrode 12 form a pair of graphene dot electrodes. The molecular bridge 2 is connected to the first graphene dot electrode 11 and the second graphene dot electrode 12 respectively through amide bonds. The molecular bridge serves as a functional unit for probability bit regulation. The molecular bridge is selected from a single four - ligand dipole molecule, and the single four - ligand dipole molecule is selected from copper complexes. The single four - ligand dipole molecule is selected from any one of the following structural formulas: , , .

[0029] According to a specific embodiment provided by the present invention, the probability bit device based on the dipole moment of a single four - ligand molecule further includes: a first metal electrode 31 and a second metal electrode 32. The first metal electrode 31 is evaporated on the first graphene dot electrode 11, and the second metal electrode 32 is evaporated on the second graphene dot electrode 12. The first metal electrode 31 and the second metal electrode 32 form a pair of metal electrodes.

[0030] According to a specific embodiment provided by the present invention, the first metal electrode 31 and the second metal electrode 32 are selected from gold electrodes.

[0031] According to a specific embodiment provided by the present invention, the probability bit device based on the dipole moment of a single four - ligand molecule further includes a protective layer 4, and the protective layer 4 covers the pair of metal electrodes and the pair of graphene dot electrodes.

[0032] According to a specific embodiment provided by the present invention, the protective layer 4 is made of hexagonal boron nitride.

[0033] A preparation method of a probability bit device based on the dipole moment of a single four - ligand molecule includes the following steps: S100: Prepare a single - layer graphene on a backing using chemical vapor deposition and oxygen plasma etching methods. S200: Prepare a graphene array electrode on the single - layer graphene using photolithography and oxygen ion etching techniques. S300: Prepare a first graphene dot electrode and a second graphene dot electrode on the graphene array electrode using electron beam lithography and etching techniques, and perform oxygen plasma etching on the first graphene dot electrode and the second graphene dot electrode to obtain a pair of graphene nano - gap dot electrodes. S400. Place the graphene nanogap point electrode pair and the tetracoordinated ligand dipole compound in a reaction system, and self-assemble a single tetracoordinated ligand dipole molecule with the graphene nanogap point electrode pair to obtain a probabilistic bit device based on the dipole moment of a single tetracoordinated ligand molecule.

[0034] In the following examples, the experimental methods used are all conventional methods unless otherwise specified. The materials, reagents, etc. used are carried out according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, they can all be obtained from commercial channels.

[0035] Example 1 Compound Ⅱ 、 Compound Ⅲ 、 Compound Ⅳ Preparation.

[0036] I. Preparation of Compound Ⅰ , the process is as follows: Under an argon atmosphere at room temperature, slowly add compound (40 mmol, 5 g), an ethanol aqueous solution with a volume ratio of 1:1 (100 ml), and ferric chloride (FeCl3·6H2O) (15 mmol, 4 g) to a 250 ml three-necked flask, and continue to stir for 12 h. Then, adjust the pH to precipitate a solid with a 1 mol / L NaOH aqueous solution, filter to obtain the crude product of compound Ⅰ . Purify the crude product by silica gel column chromatography (the elution solvent is a mixed solvent of dichloromethane and methanol with a volume ratio of 9:1), and recrystallize with ethanol to obtain the purified black-red solid compound Ⅰ ; ¹H NMR (400 MHz, DMSO-d6) δ (ppm) of Compound Ⅰ: 8.50 (d, 4H, J = 6.0 Hz), 7.10 (d, 4H, J = 6.0 Hz), 3.15 (t, 4H, J = 6.5 Hz), 2.80 (s, 4H), 65 (t, 4H, J = 6.5 Hz), 1.50 (s, 4H); ¹³C NMR (100 MHz, DMSO-d6) δ (ppm) of Compound Ⅰ: 150.5, 123.8, 142.0, 39.2, 32.4, 28.0; (TOF-ESI+) (m / z) of Compound Ⅰ: C 16 H 22 N4270.18.

[0037] II. Preparation of Compound Ⅱ , the process is as follows: Dissolve 1 mmol of CuSO4·5H2O (about 0.25 g) in 20 mL of deionized water. After stirring until completely dissolved, a blue copper sulfate solution is obtained; Dissolve compound I (2 mmol, 0.54 g) in 20 mL of a water-ethanol mixed solvent (volume ratio 1:1). After dissolution, add sodium benzenesulfonate (2 mmol, 0.44 g). After mixing evenly, a sodium benzenesulfonate solution is obtained. Slowly add this solution to the previously prepared copper sulfate solution while stirring and maintaining the temperature at about 50 °C. Adjust the pH of the reaction solution to about 7.5 with 1 wt% NaOH aqueous solution (weak alkaline conditions promote coordination). Continue stirring and reacting for about 5 h. When observing that the color of the reaction solution changes from blue to dark blue or green, stop stirring. Cool the reaction solution to room temperature, add 10 mL of ethanol to reduce the solubility, let it stand for 12 h, filter by suction to obtain a precipitate. Wash this precipitate successively with cold ethanol and ether, and dry it under vacuum to obtain a light blue powder. Purify this light blue powder by silica gel column chromatography (the elution solvent is a mixed solvent of dichloromethane and methanol with a volume ratio of 9:1). After recrystallization from ethanol, the purified compound II is obtained ; ¹H NMR (400 MHz, DMSO-d6) δ (ppm) of compound II: 8.55 (br, 4H), 7.30 (br, 4H), 3.25 (br, 4H), 2.80 (br, 4H), 2.75 (br, 4H), 1.55 (br, 4H); ¹³C NMR (100 MHz, DMSO-d6) δ (ppm) of compound II: 152.0, 124.5, 140.8, 40.1, 33.6, 28.5; (TOF-ESI+) (m / z) of compound II: C 16 H 26 CuN4O6S2 497.06.

[0038] III. Preparation of compound III , the process is as follows: Dissolve 1 mmol of CuSO4·5H2O (about 0.25 g) in 20 mL of deionized water. After stirring until completely dissolved, a blue copper sulfate solution is obtained; Compound I (2 mmol, 0.54 g) was added to 20 mL of a water-ethanol mixed solvent (volume ratio 1:1) and dissolved. Dimethyl sulfoxide (2 mmol, 0.25 mL) was added and stirred until dissolved to obtain a solution. This solution was slowly added to the previously prepared copper sulfate solution while stirring and maintaining the temperature at about 50 °C. The pH of the reaction solution was adjusted to about 7.5 with 1 wt% NaOH aqueous solution (weak alkaline conditions promote coordination), and stirring was continued for about 5 h. When the color of the reaction solution changed from blue to dark blue or green, stirring was stopped. The reaction solution was cooled to room temperature, 10 mL of ethanol was added to reduce the solubility, and it was left standing for 12 h. Then it was filtered by suction to obtain a precipitate. The precipitate was washed successively with cold ethanol and ether, and dried in vacuo to obtain a light blue powder. The light blue powder was purified by silica gel column chromatography (the elution solvent was a mixed solvent of dichloromethane and methanol with a volume ratio of 9:1), and after recrystallization from ethanol, the purified compound III was obtained. ; ¹H NMR (400 MHz, DMSO-d6) δ (ppm) of compound III: 8.59 (br, 4H), 7.39 (br, 4H), 3.55 (br, 4H), 2.83 (br, 4H), 2.65 (br, 4H), 1.47 (br, 4H); ¹³C NMR (100 MHz, DMSO-d6) δ (ppm) of compound III: 158.0, 125.5, 143.8, 40.1, 33.8, 29.5; (TOF-ESI+) (m / z) of compound III: C 16 H 24 CuN4O2S2 431.06.

[0039] IV. Preparation of compound IV , the process is as follows: 1 mmol of CuSO4·5H2O (about 0.25 g) was dissolved in 20 mL of deionized water. After stirring until completely dissolved, a blue copper sulfate solution was obtained; Compound I (2 mmol, 0.54 g) was added to 20 mL of a water-ethanol mixed solvent (volume ratio 1:1) and dissolved, and then (2 mmol, 0.3 ml). After mixing evenly, a solution was obtained. This solution was slowly added to the previously prepared copper sulfate solution while stirring and maintaining the temperature at about 50 °C. The pH of the reaction solution was adjusted to about 7.5 with 1 wt% aqueous NaOH solution (weak alkaline conditions promote coordination). Stirring was continued for about 5 h. When the color of the reaction solution changed from blue to dark blue or green, stirring was stopped. The reaction solution was cooled to room temperature, 10 mL of ethanol was added to reduce the solubility, and it was left standing for 12 h. Filtration was carried out to obtain a precipitate. This precipitate was washed successively with cold ethanol and ether, and dried in vacuo to obtain a light blue powder. The light blue powder was purified by silica gel column chromatography (the elution solvent was a mixed solvent of dichloromethane and methanol with a volume ratio of 9:1). After recrystallization from ethanol, the purified compound Ⅳ was obtained. ; ¹H NMR (400 MHz, DMSO-d6) δ (ppm) of compound Ⅳ: 8.58 (br, 4H), 7.39 (br, 4H), 3.45 (br, 4H), 2.82 (br, 4H), 2.35 (br, 4H), 1.52 (br, 4H); ¹³C NMR (100 MHz, DMSO-d6) δ (ppm) of compound Ⅳ: 152.0, 128.5, 143.8, 40.1, 38.6, 28.5; (TOF-ESI+) (m / z) of compound Ⅳ: C 20 H 24 CuF6N4O4 561.10.

[0040] Example 2 A probabilistic qubit device based on the dipole moment of a single four-coordinate molecule was prepared as follows: Single-layer graphene was obtained on a copper foil by chemical vapor deposition. The single-layer graphene was pasted onto a clean quartz wafer with transparent tape. Then, polymethylmethacrylate (PMMA) was spin-coated on the single-layer graphene. Using a spin coater, it was spin-coated at a speed of 4000 revolutions per minute for 40 s. After baking the glue at 180 °C on a heating stage for 2 min, the excess PMMA and graphene on the back of the copper foil were etched by oxygen plasma to obtain a PMMA-single-layer graphene-copper foil structure.

[0041] The PMMA-single-layer graphene-copper foil was cut into 1 cm × 1 cm small pieces and placed in a saturated ferric chloride solution to dissolve the copper foil on the back, obtaining a PMMA-supported single-layer graphene film.

[0042] The PMMA-supported single-layer graphene film was immersed in hydrochloric acid solution, aqueous solution and potassium hydroxide solution, and then transferred onto a silicon wafer covered with 350 nm thick silicon oxide. After standing, drying, and removing PMMA by heating with acetone at 120 °C, a graphene-silicon wafer layer was obtained.

[0043] Mark on the graphene-silicon wafer layer. Spin-coat photoresist on the large graphene sheet with the mark, and use a strip mask to lithograph graphene strips. After exposure and development, the strip-shaped photoresist remains to protect part of the graphene, while the remaining graphene is exposed. The exposed graphene is removed by oxygen plasma etching; then, the photoresist is removed by soaking in acetone to obtain a backing with a central graphene strip.

[0044] Lithograph electrodes on the graphene strip of the backing, and evaporate 8 nm of chromium and 60 nm of gold to obtain a graphene strip containing gold electrodes. Soak in acetone to remove the photoresist to obtain a graphene array electrode. Test the conductivity of the graphene array electrode at a voltage of 50 mV, and screen out the backing with a conductivity in the order of 10 μA for subsequent experiments.

[0045] Etch a dotted line with a length of 150 nm and a width of 5 nm on the graphene array electrode by electron beam exposure to obtain a first graphene dot electrode and a second graphene dot electrode.

[0046] Perform oxygen plasma etching on the first graphene dot electrode and the second graphene dot electrode, and use a probe station and a source meter to conduct on-off tests on each pair of electrodes. After repeating this step multiple times, a graphene nano-gap dot electrode pair is obtained.

[0047] Place the graphene nano-gap dot electrode pair in a two-necked flask, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (5 mL) and a pyridine solution of a tetracoordinated ligand dipole compound with a concentration of not less than 0.5 mM. React for 48 h in a nitrogen atmosphere to form amide covalent bonds between the -NH2 at both ends of the bottom of the tetracoordinated ligand dipole molecule and the -COOH at the ends of the graphene nano-gap dot electrode pair. Take out the device from the two-necked flask, wash it three times with deionized water and acetone respectively, and dry the surface with nitrogen for standby to obtain a probabilistic bit device based on the dipole moment of a single tetracoordinated ligand molecule. Among them, the tetracoordinated ligand dipole compound is Compound Ⅲ When, the test results of the obtained probabilistic bit device are as Figure 2 and Figure 3 shown; The tetracoordinated ligand dipole compound is selected from Compound Ⅱ When, the test results of the obtained probabilistic bit device are as Figure 4 and Figure 5 shown; The four - ligand dipole compound is selected from Compound Ⅳ When it is, the test results of the obtained probabilistic bit device are as Figure 6 and Figure 7 shown; From Figure 2 , Figure 4 and Figure 6 it can be seen that the four - ligand dipole molecule is successfully connected between the graphene nanogap point electrodes, and the molecular probabilistic bit device can be regulated accordingly by the bias voltage parameter; the molecular conductance jumps between two values, and the stable probability ratios of the two conductance states of the molecule form on a relatively long time scale; Among them, Figure 2 Figure A in shows the current change in the time range of 0 - 200 s. It can be seen from the figure that the current value fluctuates between 6 - 11 nA, showing dense and frequent current changes; Figure 2 Figure B in is a partial enlarged view of Figure A, showing the current change in the time range of 21 s - 25 s. It can be seen that the current drops and rises significantly at some moments, which may be related to the electrochemical blocking mode; Figure 2 Figure C in shows the current change at a voltage of 0.45 V. In the time range of 0 - 1000 ms, the current value is between 7 - 10 nA, and there is an obvious current drop process, which may be related to the quantum dot tunneling effect; Figure 4 Figure A in shows the current change in the time range of 0 - 200 s. It can be seen from the figure that the current value fluctuates between 4.5 nA - 8.0 nA, and the overall trend is relatively stable, but there are some small - amplitude fluctuations and changes; Figure 4 Figure B in is a partial enlarged view of Figure A, showing the current change in the time range of 20 s - 25 s. The current value rises and falls significantly in a short time, showing a pulsed characteristic, indicating that there are significant current changes within a specific time period; Figure 4 Figure C in shows the current change at a voltage of 0.45 V. The time range is from 0 - 1800 ms, and the current value fluctuates around 5.0 nA. It is relatively stable as a whole, but there is an obvious upward trend at the beginning and then tends to be stable; Figure 6 Figure A in shows the current change in the time range of 0 - 200 s. It can be seen from the figure that the current value fluctuates between 7 nA - 13 nA, and the overall trend is relatively stable but there are some sharp current drops and rises, indicating that there may be instantaneous conductance changes or impedance changes; Figure 6 Figure B in is a partial enlarged view of Figure A, showing the current change in the time range of 105 s - 110 s. It can be seen that the current drops and rises significantly in a short time, which may be related to single - molecule conductance or quantum dot tunneling effect; Figure 6Figure C in [document] shows the current change at a voltage of 0.45V. In the time range of 0 to 1000ms, the current value fluctuates around 5.0nA, which is relatively stable overall. However, there is an obvious upward trend at the initial stage and then it tends to be stable.

[0048] It can be seen from Figure 3 that during the process of the bias voltage decreasing from 0.5V to 0.3V, the proportion of the high-conductance state of a single four-coordinated ligand dipole molecule decreases from 90% to less than 10%, and the proportion of the low-conductance state increases from less than 10% to 91%. Between about 0.45V and 0.4V, the proportions of the two states of a single four-coordinated ligand dipole molecule are roughly equal, each being 50%, realizing the function of an adjustable probability bit.

[0049] It can be seen from Figure 5 that during the process of the bias voltage decreasing from 0.55V to 0.1V, the proportion of the low-conductance state of a single four-coordinated ligand dipole molecule decreases from 92% to less than 10%, and the proportion of the high-conductance state increases from less than 10% to more than 93%. At about 0.45V, the proportions of the two states of a single four-coordinated ligand dipole molecule are roughly equal, each being 50%, realizing the function of an adjustable probability bit.

[0050] It can be seen from Figure 7 that during the process of the bias voltage decreasing from 0.6V to 0.1V, the proportion of the low-conductance state of a single four-coordinated ligand dipole molecule decreases from 92% to less than 10%, and the proportion of the low-conductance state increases from less than 10% to 93%. At about 0.5V, the proportions of the two states of a single four-coordinated ligand dipole molecule are roughly equal, each being 50%, realizing the function of an adjustable probability bit.

[0051] There are many reasons for the change in conductance induced by the change of the dipole of a single four-coordinated ligand dipole molecule. The specific possible reasons are as follows: adjusting the electron transport characteristics by changing the charge distribution and local electric field within the molecule; affecting the contact potential and interface effect between the molecule and the metal electrode; changing the energy level structure and energy gap of the molecule, thereby affecting the electron injection and transmission ability; and further regulating the conductance by affecting electron tunneling and electron interaction. For the probability bit device based on the dipole moment of a single four-coordinated molecule, the proportion probabilities of the two states will change under different bias voltages, mainly because the bias voltage changes factors such as the energy level structure of electrons within the molecule, the electron injection and tunneling processes, the interaction between the molecular dipole moment and the electric field, and the thermal effect. The bias voltage changes the relative probability distribution between the two states by affecting electron transport and the relative position of energy levels within the molecule.

[0052] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A probabilistic bit device based on the dipole moment of a single tetraligand molecule, characterized in that: It includes a first graphene point electrode, a molecular bridge and a second graphene point electrode connected in sequence, wherein the first graphene point electrode and the second graphene point electrode form a graphene point electrode pair, the molecular bridge is respectively connected to the first graphene point electrode and the second graphene point electrode through an amide bond, and the molecular bridge serves as a functional unit for probability bit regulation; The molecular bridge is selected from a single tetraligand dipole molecule, and the single tetraligand dipole molecule is selected from a copper complex.

2. The probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 1, characterized in that: The single tetraligand dipole molecule is selected from any one of the following structural formulas: 、 、 。 3. The probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 1, characterized in that: The first graphene point electrode and the second graphene point electrode are nanogap point electrodes.

4. The probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 1, characterized in that: It also includes a first metal electrode and a second metal electrode, wherein the first metal electrode is evaporated on the first graphene point electrode, and the second metal electrode is evaporated on the second graphene point electrode, and the first metal electrode and the second metal electrode form a metal electrode pair.

5. The probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 4, characterized in that: The first metal electrode and the second metal electrode are selected from gold electrodes.

6. The probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 4, characterized in that: It also includes a protective layer, which covers the metal electrode pair and the graphene point electrode pair.

7. The probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 6, characterized in that: The protective layer is made of hexagonal boron nitride.

8. A method for preparing a probabilistic bit device based on a single tetraligand molecular dipole moment, characterized in that: The method for preparing a probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in any one of claims 1 to 7 comprises the following steps: S100, preparing a single layer of graphene on a backing by using a chemical vapor deposition method and an oxygen plasma etching method; S200, preparing a graphene array electrode on the single-layer graphene by using photolithography technology and peroxide plasma etching technology; S300, using electron beam exposure and etching technology to prepare a first graphene point electrode and a second graphene point electrode on the graphene array electrode, and performing oxygen plasma etching on the first graphene point electrode and the second graphene point electrode to obtain a graphene nanogap point electrode pair; S400, placing the graphene nanogap point electrode pair and the tetraligand dipole compound in a reaction system, allowing the single tetraligand dipole molecule to self-assemble with the graphene nanogap point electrode pair, and obtaining a probabilistic bit device based on the dipole moment of the single tetraligand molecule.

9. The method for preparing a probabilistic bit device based on a single tetraligand molecular dipole moment as claimed in claim 8, characterized in that: In step S400, the reaction system includes a catalyst and a reaction solvent, the catalyst is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and the reaction solvent is selected from pyridine.

10. The method for preparing a probabilistic bit device based on a single tetraligand molecular dipole moment according to claim 9, characterized in that: The concentration of the tetraligand dipole compound in the reaction system is ≥0.5 mM.

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