Materials containing electron spin and methods for producing such materials

Abstract

The present invention generally relates to novel electron spin-containing materials, and more particularly to a method for producing such materials for spatially separating electron spins from oxygen and moisture in the atmosphere.

Description

Technical Field

[0001] The present invention generally relates to novel electron spin-containing materials, and particularly to a method for preparing such materials to spatially separate electron spins from oxygen and moisture in the atmosphere.

Background Art

[0002] A computer system includes signal lines for transmitting information and memory capacitors for storing information. A voltage source charges and discharges the signal lines and memory capacitors to represent information. For example, a voltage of +5V on a signal line or a memory capacitor represents a logical value "1", and a voltage of 0V represents a logical value "0". Changing a bit between "0" and "1" involves charge transport of electrons in the form of a large number of electrons.

[0003] A more powerful way to represent information is to use the spin of a single electron. Electron spin represents a two-state quantum mechanical system, which is a basic component of a quantum computer. For example, a fullerene-based electron spin quantum device in which a fullerene molecule is in the form of a hollow carbon sphere is known in the art.

[0004] One of the most practical problems when using electron spin is that its lifetime (T , ,

[0005] ) is usually too short for room temperature applications. One solution to achieve a longer lifetime is to cool the quantum mechanical system to below 4K. This leads to a T S exceeding 100 ns. Such a long lifetime enables the electron spin to be manipulated together with the movement of charge, allowing multiple operations. However, this cooling requirement is unrealistic for commercially distributed products for home, office, and mobile applications because the product would be very large, heavy, expensive (high capital investment), and consume an excessive amount of energy.

[0005] Furthermore, electron spins in materials exposed to molecular oxygen (O2) through exposure to air or moisture have significantly shorter lifetimes compared to those measured under vacuum, due to coupling with unpaired electrons in molecular oxygen. This effect has already been reported in the literature on electron spin resonance (ESR) in carbon-based materials. The increase in the linewidth of cw-ESR (corresponding to the reduced electron spin lifetime) is a result of either the Heisenberg exchange interaction, the spin dipole-dipole interaction, or a combination of both.

[0006] The present invention provides a novel material containing electron spin that can be measured without requiring a vacuum, and the electron spin has a lifetime comparable to that expected under a vacuum or a high-purity inert gas atmosphere. [Overview of the project]

[0007] This invention is partly based on the discovery that gas-impermeable compounds such as oxides or nitrides can be applied as encapsulation or surrounding components to specific electron spin-containing materials, and that these encapsulation components can act as a so-called "virtual vacuum," which leads to the ability to maintain the lifetime of the electron spin (of the resulting encapsulated product) at a value closer to the vacuum value, even when measured under ambient conditions.

[0008] This invention relates particularly to the encapsulation of carbon nanospheres (CNS). "Carbon nanoonions (CNOs)" or "onion-like carbon (OLCs)" are carbonaceous nanostructures, typically about 10–100 nm in size, composed of multiple concentric shells of graphene and / or graphite sheets or fragments thereof, and are often referred to as CNSs. The individual graphite and / or graphene sheets or fragments within the carbon nanosphere are not curved and do not resemble the curvature of nanotubes or fullerenes. Rather, these fragments / sheets exhibit a complex arrangement of interplane bonding all the way to the center of the nanosphere, even when heated to a temperature of about 583 K. Unlike fullerenes and carbon nanotubes, carbon nanospheres do not have a hollow or tubular nature; instead, they have a continuous cage structure that closes towards the center. Those skilled in the art will understand that, in practice, CNSs are not perfectly spherical, but can be described as spherical. This has been confirmed by transmission electron microscopy observations.

[0009] However, CNSs are generally a type of nanomaterial that can exhibit long electron spin relaxation times at room temperature under various atmospheres, and are therefore promising as potential components for spintronics and quantum information processing devices. Accordingly, in relation to the present invention, “carbon nanospheres” do not simply refer to carbon nanoparticles having a spherical shape, but rather to solid, metallic carbon nanomaterials with a special structure and unique electron spin properties. As will be described in detail below, the CNSs of the present invention are synthesized by combustion of polycyclic aromatic hydrocarbons in air. A “gas-impermeable” coating is then formed by atomic layer deposition (ALD) and / or plasma-enhanced chemical vapor deposition (PECVD), followed by annealing under a high vacuum environment. This coating is designed to create vacuum-like conditions to protect electron spins within the core material for applications in quantum spintronics and quantum processing devices.

[0010] In one embodiment, the CNS used in the present invention is not hollow, and the CNS contains delocalized metallic electron spin states throughout its entire volume, the electron spin states having an itinerant nature (freely moving around, itinerant in nature), and in some cases having an electron spin lifetime of about 115 nanoseconds at room temperature, and the CNS further comprises short graphite fragments that form an unclosed shell along the curvature of the sphere.

[0011] In another embodiment, the CNS used in the present invention comprises short graphite fragments having a diameter of 20 nm to 55 nm, which are not hollow and form an open shell along the curvature of the nanosphere, and the carbon nanosphere exhibits a complex arrangement of interplane bonding to the center of the nanosphere, thereby resulting in a conductive homogeneous material that is structurally highly amorphous (i.e., non-crystalline), and thereby the carbon nanosphere has a delocalized metallic electron spin state along the entire diameter of the carbon nanosphere, and the electron spin state has an itinerant nature, and in some cases the electron spin lifetime at room temperature is about 115 nanoseconds.

[0012] For differences in spin properties between CNS and other systems (including fullerenes), see Nafradi et al., Nature Communications, Vol. 7, paper number 12232 (2016). Diagram 1 by Nafradi et al. (below): Compares itinerant and localized electron-based qubits, including the metallic carbon nanosphere (a) used in the present invention. JPEG2026521164000001.jpg155131

[0013] In the diagram above, (a) represents the itinerant spin system of the proposed carbon nanosphere (CNS), which is the subject of the present invention. The shaded circles indicate that electrons are delocalized (itinerant) throughout the system. This is contrasted with the localized systems of (b) N@C60 (fullerene), (c) NV nanodiamond, and (d) Si:P. The spin information in the CNS is encoded by delocalized electron spins spread across the entire diameter, making the system more robust to hyperfine interactions caused by fluctuations in the external magnetic field and nuclear spins. In this way, a high qubit density can be achieved without increasing decoherence. Section (e) shows the diameters of spheres, along with a scale bar (100 nm), comparing the volumes required for different types of qubits.

[0014] A key difference from the teachings of Nafradi et al. is that the CNS particles of the present invention are encapsulated by a coating layer, which allows the ESR to be measured in air or ambient atmosphere, and enables quantum devices fabricated from the encapsulated CNS particles to operate in air or ambient atmosphere rather than in vacuum. This is because the encapsulated CNS particles maintain an electron spin lifetime at room temperature that is equivalent to or close to the spin lifetime measured in vacuum.

[0015] For example, in one embodiment, the variation in spin lifetime between measurements under vacuum and under ambient conditions for encapsulated CNS particles of the present invention is measured by the cw-ESR linewidth in Gauss and is only about 0.01 to 0.5 Gauss. Typically, in a particular embodiment, unmodified CNS particles encapsulated in silicon nitride and sealed in vacuum are characterized by having a linewidth of about 0.97 Gauss, and even if the seal is broken (i.e., the particles are exposed to the atmosphere), the broadening of the linewidth is limited to about 1.2 Gauss (i.e., the variation is only about 0.23 Gauss).

[0016] Those skilled in the art understand that ESR linewidth measurements can be converted to actual lifetime measurements in T1 and T2 nanosecond units, an example of which is described in "Relaxation in Magnetic Resonance" by Poole Jr, CP and Farach, HA (editors: Charles P. Poole and Horacio A. Farach), pp. 17-29, Academic Press, 1971, which is incorporated herein by reference in its entirety.

[0017] For example, 0.97 gauss is equivalent to approximately 67.57 nanoseconds, and 1.2 gauss is equivalent to approximately 54.62 nanoseconds.

[0018] In one embodiment, the present invention provides individual encapsulated carbon nanosphere particles or aggregates thereof, comprising a carbon nanosphere core and an outer coating layer for encapsulation containing one or more gas-impermeable compounds, wherein the coating layer has a thickness of about 5 to 50 nm, and optionally, the encapsulated carbon nanosphere particles or aggregates thereof are bonded to the surface of a solid substrate.

[0019] In a further embodiment, the present invention provides encapsulated carbon nanosphere particles comprising a carbon nanosphere core and an outer coating layer for encapsulation containing one or more gas-impermeable compounds, wherein the coating layer has a thickness of about 5 to 50 nm.

[0020] In another embodiment, the present invention provides an encapsulated aggregate of carbon nanosphere particles comprising 2 billion to 100 billion carbon nanosphere particles, wherein the carbon nanosphere particles comprise an outer coating layer for encapsulation containing a carbon nanosphere core and one or more gas-impermeable compounds, the coating layer having a thickness of about 5 to 50 nm. [Brief explanation of the drawing]

[0021] Shows the continuous wave (CW) ESR spectra of encapsulated CNS samples in both the sealed state in vacuum and the unsealed state, with fitting by a Lorentz + Gaussian composite function and the insertion of fitting parameters. [Figure 1a] A sample encapsulated with about 20 nm of aluminum oxide and sealed in vacuum, showing a linewidth of about 0.940 Gauss. [Figure 1b] The same sample after releasing the vacuum seal, showing an essentially unchanged linewidth of about 0.935 Gauss. [Figure 1c] A sample encapsulated with about 50 nm of silicon nitride and sealed in vacuum, showing a linewidth of about 0.971 Gauss. [Figure 1d] The same sample after releasing the vacuum seal, showing a broadened linewidth of about 1.22 Gauss.

[0022] Detailed description In certain embodiments, the present invention provides carbon nanospheres and / or carbon nanosphere aggregates, where individual carbon nanospheres or aggregates are sufficiently or substantially encapsulated or surrounded by a gas-impermeable compound such as an oxide or nitride. Thus, it is understood that the present invention contemplates encapsulating either individual carbon nanosphere particles or aggregates containing 2 billion to 100 billion carbon nanosphere particles.

[0023] In certain embodiments, the CNS particles are doped or undoped CNS particles, and are then encapsulated.

[0024] CNS particles can be doped with one or more heteroatoms, including but not limited to boron, nitrogen, oxygen, fluorine, silicon, phosphorus, sulfur, and selenium. Doping is a widely used technique to alter the properties of untreated carbon-based materials, particularly their electronic structure. Such doping can be achieved by various methods, including chemical vapor deposition (CVD), chemical doping, ball milling, ultraviolet (UV) or microwave treatment, and electrochemical methods (References: Kim et al., Scientific Reports, Vol. 7, No. 14400 (2017); Ahmed et al., General Doping Chemistry of Carbon Materials, Chemnanomat, Vol. 9, No. 4, April 2023; and Hao et al., J. Mater. Chem. A, 2018, Vol. 6, pp. 8053-8058).

[0025] In another embodiment, the present invention provides a quantum electronic device element comprising an encapsulated carbon nanosphere or aggregate thereof adapted to store qubits represented by electron spins, and a control and readout device for setting and reading out qubits stored in the encapsulated carbon nanosphere or aggregate thereof.

[0026] In other embodiments, the present invention provides a quantum electronic device, which is described below: Individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof as described herein, adapted to store qubits represented by electron spin; and Control and readout device for setting up qubits and reading qubits stored in carbon nanospheres or aggregates thereof. The carbon nanospheres contain short graphite fragments that form an open shell along the curvature of the nanosphere, with each individual carbon nanosphere particle having a diameter of 20 nm to 55 nm and being not hollow. The carbon nanospheres exhibit a complex arrangement of interplane bonds extending to the center of the nanosphere, thereby resulting in a conductive homogeneous material that is structurally highly amorphous. Thus, each individual carbon nanosphere particle or its aggregate has a metallic electron spin state that is delocalized across the entire diameter of the individual carbon nanosphere particle, and the electron spin state has an itinerant nature, with an electron spin lifetime of approximately 115 nanoseconds at room temperature, depending on the case.

[0027] In other specific embodiments, the electron spin state is itinerant, the electron spin lifetime at room temperature is about 115 nanoseconds, and for the encapsulated CNS particles of the present invention, the variation in spin lifetime between measurements under vacuum and measurements under ambient atmosphere conditions is measured by the cw-ESR linewidth in Gauss and is only about 0.05 to 0.5 Gauss.

[0028] An advantage of encapsulated carbon nanospheres or aggregates containing qubits is that they have long electron spin lifetimes at room temperature and under atmospheric conditions. For example, Nafradi et al. reported that the electron spin lifetime of uncoated (and undoped) CNS is approximately 115 nanoseconds under vacuum, but when exposed to air, the lifetime decreases significantly (to about 2-5 nanoseconds). This is thought to be due not only to the effect of pressure differences but also to exposure to oxygen and moisture in the atmosphere.

[0029] In one embodiment, one or more gas-impermeable compounds are selected from the group consisting of aluminum oxide, silicon nitride, silicon dioxide, silicon carbide, aluminum nitride, aluminum oxynitride, titanium oxynitride, titanium dioxide, titanium nitride, and boron nitride.

[0030] In one embodiment, one or more gas-impermeable compounds are aluminum oxide.

[0031] In one embodiment, one or more gas-impermeable compounds are silicon nitride.

[0032] In one embodiment, one or more gas-impermeable compounds are silicon dioxide.

[0033] In one embodiment, one or more gas-impermeable compounds are silicon carbide.

[0034] In one embodiment, one or more gas-impermeable compounds are aluminum nitride.

[0035] In one embodiment, one or more gas-impermeable compounds are aluminum oxynitride.

[0036] In one embodiment, one or more gas-impermeable compounds are titanium oxynitride.

[0037] In one embodiment, one or more gas-impermeable compounds are titanium dioxide.

[0038] In one embodiment, one or more gas-impermeable compounds are titanium nitride.

[0039] In one embodiment, one or more gas-impermeable compounds are boron nitride.

[0040] In certain embodiments, encapsulation is a monolayer encapsulation using the single gas-impermeable encapsulating compound described above. In one embodiment, the encapsulated carbon nanosphere particles or aggregates thereof of the present invention are characterized by electron spin resonance in a non-vacuum ambient atmosphere, with a difference of only about 0.01 to 0.5 gauss or about 0 to 0.250 gauss compared to the same unencapsulated carbon nanosphere particles or aggregates thereof under vacuum conditions at the same temperature.

[0041] In one embodiment, the encapsulated carbon nanosphere particles or aggregates thereof of the present invention are characterized by having an electron spin lifetime difference of only about 0 to 30 ns compared to the same unencapsulated carbon nanosphere particles under the same vacuum conditions at the same temperature.

[0042] Therefore, in a further embodiment, the present invention provides a method for preparing encapsulated carbon nanospheres, the method being: 1) Dispersing carbon nanospheres in a nonpolar solvent; 2) Coating carbon nanospheres with a gas-impermeable encapsulating compound to produce encapsulated carbon nanospheres having a coating layer with a thickness of approximately 5 to 50 nm; and 3) To remove the gas trapped from the coating layer of the encapsulated carbon nanospheres, subject the encapsulated carbon nanospheres to an annealing treatment; Includes.

[0043] In one embodiment, the nonpolar solvent is selected from the group consisting of pentane, hexane, heptane, benzene, toluene, and xylene.

[0044] In one embodiment, the nonpolar solvent is toluene.

[0045] In one embodiment, the dispersion step involves carbon nanospheres in a nonpolar solvent at a concentration of approximately 1 mg / mL to approximately 10 mg / mL.

[0046] In one embodiment, the annealing process is carried out at approximately 150-250°C for approximately 20-60 minutes under high vacuum (approximately 10°C). -4 From about 10 -7 This is performed in mBar.

[0047] In one embodiment, the annealing process is carried out at approximately 150-250°C for approximately 20-40 minutes under high vacuum (approximately 10°C). -6 This is performed in mBar.

[0048] In one embodiment, carbon nanospheres may be characterized by a spherical diameter of 20–200 nm. Larger spherical diameters may result in longer spin lifetimes. Therefore, in one embodiment, the spherical diameter may be about 50–150 nm.

[0049] In yet another embodiment, the present invention provides encapsulated carbon nanosphere particles comprising a carbon nanosphere core and an outer coating layer for encapsulation containing one or more gas-impermeable compounds, wherein the coating layer has a thickness of about 5 to 50 nm, and the encapsulated carbon nanosphere particles are bonded to the surface of a solid substrate.

[0050] In another embodiment, the present invention provides an encapsulated aggregate of carbon nanosphere particles comprising 2 billion to 100 billion carbon nanosphere cores and an outer coating layer for encapsulation containing one or more gas-impermeable compounds, wherein the coating layer has a thickness of about 5 to 50 nm, and the encapsulated carbon nanosphere aggregate is bonded to the surface of a solid substrate.

[0051] In certain embodiments, the substrate surface is quartz (SiO2), GaAs, AlGaAs, InGaAs, InAsSbP, Si, silicon on an insulator (SOI), Al2O3 (sapphire), polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), or other semicrystalline thermoplastic substrate material.

[0052] Therefore, in yet another embodiment, the present invention provides a method for preparing encapsulated carbon nanospheres bonded to a solid substrate, the method being: 1) A step of dispersing carbon nanospheres in toluene; 2) a. Washing with acetone, then isopropyl alcohol (IPA), and then drying with an inert gas, and b. Oxygen plasma ashing at a pressure of approximately 300-450 mTorr A step of depositing (or adhering) a dispersion from 1) onto a solid substrate that has been pretreated by , thereby forming a carbon nanosphere deposit (or adhering) on ​​the solid substrate; 3) A step of coating the sediment obtained in step 2) with a gas-impermeable encapsulating compound to produce encapsulated carbon nanospheres having a coating layer with a thickness of approximately 5 to 50 nm; and 4) A step of subjecting the encapsulated carbon nanospheres bonded to a solid support to an annealing treatment in order to discharge the gas trapped from the coating layer of the encapsulated carbon spheres. Includes.

[0053] In one embodiment, the dispersion in step 2) is a toluene dispersion of carbon nanospheres in a concentration of approximately 1 mg / mL to approximately 10 mg / mL.

[0054] In one embodiment, the solid substrate surface is a quartz slide cut to fit a 4 mm ESR tube prior to step 2).

[0055] In one embodiment, the oxygen plasma ashing process is carried out for 5 minutes in an O2 plasma asher glow (Plasma O2) at a pressure of approximately 300-450 mTorr and an output of approximately 50 W in order to remove any remaining organic matter.

[0056] In one embodiment, the annealing process is carried out at approximately 150-250°C for approximately 20-40 minutes under high vacuum (approximately 10°C). -6 The measurement is performed in a quartz ESR tube at mBar. The quartz ESR tube can be used to measure the sample afterward.

[0057] In one embodiment, carbon nanospheres may be characterized by a spherical diameter of 20–200 nm. Larger spherical diameters may result in longer spin lifetimes. Therefore, in one embodiment, the spherical diameter may be approximately 50–150 nm.

[0058] The present invention further provides a quantum electronic device, which is described below: Individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof according to the present invention, adapted to store qubits represented by electron spin; and Control and readout device for setting up qubits and reading qubits stored in carbon nanospheres or aggregates thereof. The carbon nanospheres contain short graphite fragments that form an open shell along the curvature of the nanosphere, with each individual carbon nanosphere particle having a diameter of 20 nm to 55 nm and being not hollow. The carbon nanospheres exhibit a complex arrangement of interplane bonds extending to the center of the nanosphere, thereby resulting in a conductive homogeneous material that is structurally highly amorphous. Thus, each individual carbon nanosphere particle or its aggregate has a delocalized metallic electron spin state along the entire diameter of the individual carbon nanosphere particle, and this electron spin state has an itinerant nature, with an electron spin lifetime of approximately 115 nanoseconds at room temperature, depending on the case.

[0059] In one embodiment, each carbon nanosphere particle has a diameter of 35 nm.

[0060] In one embodiment, the quantum electronic device has carbon nanosphere particles or aggregates thereof at temperatures between -40 degrees Celsius and +40 degrees Celsius.

[0061] In one embodiment, the quantum electronic device is a spintronic device having a plurality of encapsulated carbon nanospheres, each carbon nanosphere adapted to provide a qubit represented by the electron spin within the carbon nanosphere. The control device is configured to facilitate interactions between qubits on multiple encapsulated carbon nanospheres in order to perform quantum operations.

[0062] In one embodiment, the quantum electronic device further includes a conductor coupled to carbon nanospheres to provide electron transport for carrying electron spins.

[0063] In one embodiment, the conductor includes a graphene structure.

[0064] In certain embodiments, the quantum electronic device further includes electrodes associated with each of a plurality of encapsulated carbon nanospheres.

[0065] In one embodiment, the quantum electronic device further includes an insulating layer for insulating the electrodes from a plurality of encapsulated carbon nanospheres.

[0066] In one embodiment, the insulating layer has a thickness of 200 nm to 400 nm.

[0067] In one embodiment, the insulating layer includes an SiO2 layer.

[0068] In one embodiment, the distance between multiple encapsulated carbon nanospheres is such that no spin is lost during transport between the multiple encapsulated carbon nanospheres.

[0069] In one embodiment, the distance between multiple encapsulated carbon nanospheres is 50 nm to 1,000 nm.

[0070] In another embodiment, the present invention envisions using the encapsulated carbon nanospheres of the present invention for the fabrication of quantum electronic devices.

[0071] And finally, the present invention also envisions a method for quantum computing, the method being: To store qubits represented by electron spin on individual encapsulated carbon nanosphere particles or aggregates thereof in a quantum electronic device according to the present invention; and Performing quantum operations on qubits to generate qubit results; and reading out qubit results from individual encapsulated carbon nanosphere particles or aggregates thereof; Includes.

[0072] Throughout this specification, variations such as “comprise” or “comprises” or “comprising” are understood to include the elements, integers, or steps described, or the group of elements, integers, or steps, but not to exclude any other elements, integers, or steps, or the group of elements, integers, or steps.

[0073] The present invention will be described below with reference to the following non-limiting embodiments.

[0074] Examples Preparation of CNS The synthesis of carbon nanospheres may involve the flash pyrolysis of naphthalene or other polycyclic aromatic hydrocarbon vapors on a glass or ceramic substrate. This may involve heating 0.5 g of naphthalene (M&B Chemicals) in air to its flash point (approximately 79-87°C), and then continuously igniting the resulting vapor using a direct flame. The resulting carbon material may be collected on a glass or ceramic dish, and any remaining naphthalene may be removed by heating the sample in a vacuum oven at 200°C for 24 hours. The synthesis yields 0.4 g of CNS flakes per hour (20% carbon recovery rate). The sample may be further heated under dynamic vacuum for 12 hours up to a maximum of 600°C.

[0075] Sample preparation and encapsulation process Samples were prepared for encapsulation by dispersing CNS material in toluene at a concentration of 2 mg / mL. Quartz slides were cut to fit 4 mm diameter ESR tubes, washed with acetone and isopropyl alcohol (IPA), and then dried with a nitrogen gun. Next, to remove any remaining organic matter, oxygen plasma ashing was performed for 5 minutes in an O2 plasma asher glow (Plasma O2) at a pressure of approximately 350-400 mTorr and an output of 50 W. Subsequently, in a cleanroom environment, 0.5 μL droplets were added to each quartz slide using a mechanical pipette.

[0076] Aluminum oxide was deposited using trimethylaluminum and water, with a PicoSun R200 atomic layer deposition (ALD) system, at 150°C and 5-6 mTorr for approximately 250 cycles, resulting in an oxide thickness of 20 nm.

[0077] Alternatively, silicon nitride (SiN) deposition was carried out using silane (SiH4), ammonia (NH3), and nitrogen (N2) as precursors on an Oxford Instruments PlasmaPro 100 PECVD module at 300°C and 650 mTorr, at a rate of approximately 1 minute per 15.3 nanometers of layer thickness.

[0078] After deposition, the sample was subjected to plasma ashing again using the same conditions as described above to remove unencapsulated CNS material.

[0079] After encapsulation, the sample was subjected to post-deposition annealing (PDA) to ensure that the captured gas diffused outside the coating layer. Annealing was performed under high vacuum (approximately 10°C) inside a quartz ESR tube where the sample would later be measured. -6 The test was performed at 200°C for approximately 20-40 minutes at mBar.

[0080] Subsequently, to measure the baseline, the samples were sealed under vacuum in ESR tubes. The quality of encapsulation was then evaluated by comparing the sealed samples with identical (or equivalent) samples measured in an unsealed state, i.e., non-vacuum state, to the degree of minimal ESR linewidth broadening. ESR linewidth was measured in the X-band (approximately 9.6 GHz) and at room temperature using a Bruker EMXPlus EPR spectrometer.

[0081] Synthesis of B-doped CNS The typical procedure for synthesizing boron-doped CNS includes the following steps: 1.5 mg of untreated CNS prepared by the method described above is mixed with 2.5 mg of boric acid by mechanical milling. The mixture is then sealed in a quartz tube (4 mm in diameter, 250 mm in length) under vacuum conditions. The sealed tube is subjected to annealing treatment at 900°C for 2 hours in a vacuum tube furnace. After annealing, the powder sample is washed and dried to prepare it for further characterization.

Claims

1. The invention comprises a carbon nanosphere core and a coating outer layer containing one or more gas-impermeable compounds, the coating layer having a thickness of approximately 5 to 50 nm, and further, optionally, the coated carbon nanosphere particles or aggregates thereof are bonded to the surface of a solid substrate, comprising individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof.

2. The CNS particles are synthesized by the combustion of polycyclic aromatic hydrocarbons in air, as described in claim 1, for individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof.

3. The individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof according to claim 1 or 2, wherein a coating layer is formed via atomic layer deposition (ALD) and / or plasma-enhanced chemical vapor deposition (PECVD), followed by annealing in a high vacuum environment.

4. Individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof according to any one of claims 1 to 3, wherein the CNS particles have a diameter of 20 nm to 55 nm.

5. An individual encapsulated carbon nanosphere particle or aggregate thereof according to any one of claims 1 to 3, comprising a carbon nanosphere core and an outer coating layer for encapsulation containing one or more gas-impermeable compounds, the coating layer having a thickness of about 5 to 50 nm, wherein each individual encapsulated carbon nanosphere particle or aggregate thereof has a delocalized metallic electron spin state over the overall diameter of the individual carbon nanosphere particle.

6. The individual encapsulated carbon nanosphere particles or aggregates thereof according to claim 5, wherein the electron spin state has an itinerant nature and the electron spin lifetime at room temperature is about 115 nanoseconds.

7. Individual encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 6, comprising doped carbon nanospheres.

8. The dopant is selected from boron, nitrogen, oxygen, fluorine, silicon, phosphorus, sulfur, and selenium, and the individual encapsulated carbon nanosphere particles or aggregates thereof according to claim 7.

9. The individual encapsulated carbon nanosphere particles or aggregates thereof according to claim 6, wherein the dopant is boron.

10. An individual encapsulated carbon nanosphere particle or aggregate thereof according to any one of claims 1 to 5, comprising undoped carbon nanospheres.

11. A coated aggregate of carbon nanosphere particles according to any one of claims 1 to 10, comprising 2 billion to 100 billion carbon nanosphere particles containing a carbon nanosphere core, and an encapsulated outer coating layer comprising one or more gas-impermeable compounds, wherein the coating layer has a thickness of approximately 5 to 50 nm.

12. The encapsulated carbon nanosphere particle according to claim 1, comprising a carbon nanosphere core and an outer coating layer for encapsulation containing one or more gas-impermeable compounds, wherein the coating layer has a thickness of about 5 to 50 nm, and further comprising encapsulated carbon nanosphere particles bonded to the surface of a solid substrate.

13. An encapsulated aggregate of carbon nanosphere particles according to claim 1, comprising carbon nanosphere particles having 2 billion to 100 billion carbon nanosphere cores, and comprising an outer coating layer for encapsulation containing one or more gas-impermeable compounds, wherein the coating layer has a thickness of about 5 to 50 nm, and further comprising encapsulated carbon nanosphere aggregates bonded to the surface of a solid substrate.

14. A quantum electronic device component comprising encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 13, adapted to store qubits represented by electron spin; and A quantum electronic device component comprising a control and readout device for setting up qubits and reading qubits stored in encapsulated carbon nanosphere particles or aggregates thereof.

15. An encapsulated carbon nanosphere particle or aggregate thereof according to any one of claims 1 to 14, characterized in that the difference in electron spin lifetime is about 0 to 30 ns compared to an unencapsulated carbon nanosphere particle or aggregate thereof under vacuum conditions at the same temperature.

16. The substrate surface is made of silica (SiO ２ ), GaAs, AlGaAs, InGaAs, InAsSbP, Si, silicon on insulator (SOI), Al ２ O ３ The encapsulated carbon nanosphere particles or aggregates thereof according to claim 12 or 13, wherein the substrate material is (sapphire), polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), or another semicrystalline thermoplastic substrate material.

17. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are aluminum oxide.

18. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are silicon nitride.

19. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are silicon dioxide.

20. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are silicon carbide.

21. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are aluminum nitride.

22. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are aluminum oxynitride.

23. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are titanium oxynitride.

24. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are titanium dioxide.

25. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are titanium nitride.

26. The encapsulated carbon nanosphere particles or aggregates thereof according to any one of claims 1 to 16, wherein one or more gas-impermeable compounds are boron nitride.

27. The encapsulation is a single-layer encapsulation using a single gas-impermeable compound, according to any one of claims 1 to 26, for encapsulated carbon nanosphere particles or aggregates thereof.

28. An encapsulated carbon nanosphere particle or aggregate thereof according to any one of claims 1 to 27, characterized in that it has electron spin resonance in a non-vacuum ambient atmosphere, and the difference compared to the same unencapsulated carbon nanosphere particle or aggregate thereof under vacuum conditions at the same temperature is only about 0.01 to 0.5 Gauss.

29. An encapsulated carbon nanosphere particle or aggregate thereof according to any one of claims 1 to 27, characterized in that it has electron spin resonance in a non-vacuum ambient atmosphere, and the difference is only about 0 to 0.250 gauss when compared to the same unencapsulated carbon nanosphere particle or aggregate thereof under vacuum conditions at the same temperature.

30. A method for preparing encapsulated carbon nanospheres bonded to a solid substrate, 1) Dispersing carbon nanospheres in toluene; 2) a. Wash with acetone, then isopropyl alcohol (IPA), and then dry with an inert gas; and b. Oxygen plasma ashing at a pressure of approximately 300–450 mTorr. A dispersion from 1) is deposited onto a solid substrate that has been pretreated by the above method to form a carbon nanosphere deposit on the solid substrate. 3) Coating the deposit from step 2) with one or more gas-impermeable encapsulating compounds to produce encapsulated carbon nanospheres having a coating layer with a thickness of approximately 5 to 50 nm, and 4) In order to remove the gas trapped in the coating layer of the encapsulated carbon nanospheres, the encapsulated carbon nanospheres bonded to a solid support are subjected to an annealing treatment. A method that includes this.

31. The method according to claim 30, wherein the dispersion in step 2) is a toluene dispersion of carbon nanospheres in a concentration of approximately 1 mg / mL to approximately 10 mg / mL.

32. The oxygen plasma ashing process uses a pressure of approximately 300-450 mTorr and an output of approximately 50 W to remove residual organic matter. ２ Plasma Asher Glow (Plasma O ２ The method according to claim 30 or 31, which is performed for 5 minutes in )

33. The annealing process is carried out at approximately 150-250°C for approximately 20-40 minutes under high vacuum (approximately 10°C). －６ The method according to any one of claims 30 to 32, wherein the procedure is performed in a quartz ESR tube in which the sample can be measured later, at mBar.

34. 1) Dispersing carbon nanospheres in a nonpolar solvent; 2) Coating carbon nanospheres with one or more gas-impermeable encapsulating compounds to produce encapsulated carbon nanospheres having a coating layer with a thickness of about 5 to 50 nm; and 3) In order to remove the gas trapped from the coating layer of the encapsulated carbon nanospheres, subject the encapsulated carbon nanospheres to an annealing treatment. A method for preparing encapsulated carbon nanospheres containing [a specific substance].

35. The method according to claim 33, wherein the nonpolar solvent is selected from the group consisting of pentane, hexane, heptane, benzene, toluene, and xylene.

36. The method according to claim 35, wherein the nonpolar solvent is toluene.

37. The dispersion step relates to carbon nanospheres in a nonpolar solvent at a concentration of about 1 mg / mL to about 10 mg / mL, as described in claim 35 or 36.

38. In an embodiment of the annealing process, the annealing process is carried out at approximately 150-250°C for approximately 20-60 minutes under high vacuum (approximately 10°C). －４ ~about 10 －７ The method according to any one of claims 34 to 37, carried out in mBar.

39. In an embodiment of the annealing process, at about 150 to 250 °C for about 20 to 40 minutes, under high vacuum (about 10 －６ mBar), the method according to any one of claims 34 to 37.

40. The encapsulated carbon nanosphere particles or aggregates thereof, or method according to any one of claims 1 to 39, characterized in that the carbon nanospheres have a spherical diameter of about 20 to 200 nm.

41. The encapsulated carbon nanosphere particles or aggregates thereof or method according to claim 38, characterized in that the carbon nanospheres may have a spherical diameter of about 50 to 150 nm.

42. Individual encapsulated carbon nanosphere (CNS) particles or aggregates thereof according to any one of claims 1 to 29 or 41, adapted to store qubits represented by electron spin; and Includes a control and readout device for setting up a qubit and reading out a qubit stored in a carbon nanosphere or its aggregate, Each carbon nanosphere particle has a diameter of 20 nm to 55 nm and contains short graphite fragments that form an open shell along the curvature of the nanosphere, rather than being hollow. The carbon nanosphere exhibits a complex arrangement of inter-plane bonding up to the center of the nanosphere, thereby resulting in a conductive homogeneous material that is structurally highly amorphous. Thus, each carbon nanosphere particle or aggregate thereof has a delocalized metallic electron spin state across the entire diameter of the individual carbon nanosphere particle, and the electron spin state has an itinerant nature, with an electron spin lifetime of approximately 115 nanoseconds at room temperature, depending on the case, forming a quantum electronic device.

43. The quantum electronic device according to claim 42, wherein each carbon nanosphere particle has a diameter of 35 nm.

44. The carbon nanosphere particles or aggregates thereof, at temperatures between -40°C and +40°C, constitute the quantum electronic device according to claims 42 and 43.

45. Storing qubits represented by electron spin in individual encapsulated carbon nanosphere particles or aggregates thereof in the quantum electronic device according to any one of claims 1 to 29 or 41; Performing quantum operations on qubits to generate qubit results; and Reading qubit results from individual encapsulated carbon nanosphere particles or aggregates thereof, A method for quantum computing, including...

46. The quantum electronic device is a spintronic device having multiple encapsulated carbon nanospheres adapted to provide qubits represented by electron spin within each carbon nanosphere. The control device facilitates the interaction between qubits on multiple encapsulated carbon nanospheres in order to perform quantum computations. A quantum electronic device according to any one of claims 40 to 42.

47. The quantum electronic device according to claim 46, further comprising a conductor bonded to carbon nanospheres that provides electron transport for carrying electron spin.

48. The quantum electronic device according to claim 47, wherein the conductor includes a graphene structure.

49. The quantum electronic device according to claim 47 or 48, further comprising electrodes associated with each of the multiple encapsulated carbon nanospheres.

50. The quantum electronic device according to claim 49, further comprising an insulating layer for insulating electrodes from a plurality of encapsulated carbon nanospheres.

51. The quantum electronic device according to claim 50, wherein the insulating layer has a thickness between 200 nm and 400 nm.

52. The insulating layer is SiO ２ A quantum electronic device according to claim 50 or 51, comprising a layer.

53. The quantum electronic device according to any one of claims 42-44 or 45-52, wherein the distance between the multiple encapsulated carbon nanospheres is such that no spin is lost during transport between the multiple encapsulated carbon nanospheres.

54. The quantum electronic device according to claim 53, wherein the distance between the multiple encapsulated carbon nanospheres is 50 nm to 1,000 nm.

55. Use of encapsulated carbon nanospheres for the manufacture of a quantum electronic device according to any one of claims 42 to 44 or 46 to 54.

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