Superconducting materials and methods for producing them

Abstract

A superconducting material and method for making the same is described, in which the superconducting material is grown on a crystalline substrate having a lattice parameter that imparts a strain to the superconducting material that reduces the applied pressure at which the superconducting material exhibits superconductivity.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the interests of U.S. Provisional Patent Application No. 63 / 058,324, filed July 29, 2020. This application is also partially related in subject matter to International Application No. PCT / US21 / 42447, filed July 20, 2021. To the extent permitted in the applicable jurisdiction, the entire contents of these applications are incorporated herein by reference, as are all publications cited below.

[0002] This disclosure relates to superconducting materials and methods for fabricating superconducting materials using molecular beam epitaxy (MBE). [Background technology]

[0003] Superconductivity has been known for over 100 years. However, materials developed to date do not exhibit superconductivity under ambient conditions close enough to those required for many practical applications. To utilize the significant potential benefits of superconductivity on a larger scale, it is necessary to develop materials that can exhibit superconductivity under commercially viable temperature and pressure conditions.

[0004] The exploration, synthesis, and structural and physical characterization of novel metallic superhydrides with high superconducting transition temperatures necessary to observe room-temperature superconductivity (RTSC), as well as understanding methods for obtaining metastable pathways for their recovery to ambient conditions, are crucial for advancements in materials science and energy transfer technologies. Limitations on energy storage from renewable energy technologies can be overcome by superconductors, which provide highly efficient means of storing and recovering energy on demand, as well as methods for transferring energy over long distances. Robust superconductors suitable for constructing Josephson junction quantum logic gates capable of operating at higher temperatures have the potential to provide innovative novel switching mechanisms for computation.

[0005] Furthermore, many of today's quantum systems (including, for example, qubits, superconducting materials, and topological systems) can be difficult to reliably match with classical (e.g., non-quantum) systems, partly due to abrupt thermal transitions. In this regard, the scalability of these complex systems can be significantly limited by the challenge of managing their thermal load at cryogenic operating temperatures. Reliable non-cryogenic or even room-temperature quantum components would help overcome many of these difficulties, and these materials would be essential for quantum computing systems (for example, to allow coherent manipulation of electrons in spin quantum computers).

[0006] Conventional superconductivity at higher temperatures in hydrogen-rich materials has been reported in several systems under high pressure (Drozdov, AP, Eremets, MI, Troyan, IA, Ksenofontov, V, and Shylin, SI. Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system, Nature 525, 73-76 (2015) ("Drozdov 1"); Drozdov, AP et al., Superconductivity at 250 K in lanthanum hydride under high pressures, Nature 569, 528-531 (2019) ("Drozdov 2"); and Somayazulu, M et al., Evidence for Superconductivity above 260 K in Lanthanum Superhydride at Megabar Pressures, Phys. Rev. Lett. 122, 27001 (2019).[4] See Bi, T., Zarifi, N., Terpstra, T., and Zurek, E. The Search for Superconductivity in High Pressure Hydrides, Reference Module in Chemistry, Molecular Sciences and Chemical Engineering (Elsevier, 2019), doi:10.1016 / B978-0-12-409547-2.11435-0. However, these materials do not exhibit superconductivity at the pressure and temperature combinations required for most commercial applications. This disclosure addresses this need. [Overview of the Initiative]

[0007] Superconducting structures and methods for manufacturing them are provided herein.

[0008] In some embodiments, the disclosure provides a method comprising the steps of providing a crystalline substrate including a growth surface having a set of lattice parameters, and growing a solid hydride material on the growth surface, wherein the set of lattice parameters imparts a strain to the solid hydride material that reduces the applied pressure at which the solid hydride material exhibits superconductivity.

[0009] In another embodiment, the disclosure provides a superconducting structure comprising a crystalline substrate including a growth surface having a set of lattice parameters, and a solid hydride material formed on the crystalline substrate, wherein the set of lattice parameters of the crystalline substrate imparts a strain to the solid hydride material that reduces the applied pressure at which the solid hydride material exhibits superconductivity.

[0010] In some embodiments, the solid hydride material comprises a metal or a metallic crystal containing carbon, sulfur, and hydrogen. In some embodiments, the step of providing a crystalline substrate comprises growing a diamond structure by chemical vapor deposition. In one embodiment, the grown surface is parallel to the (110) or (121) lattice planes of the diamond structure (where "(110)" and "(121)" indicate the Miller indices of the lattice planes).

[0011] In some embodiments, the step of providing a crystalline substrate further includes replacing carbon atoms in the grown diamond structure by substitution doping with boron (B), sulfur (S), phosphorus (P), hydrogen sulfide (H2S), or a combination thereof. In some embodiments, substitution doping includes focused ion beam deposition of B, S, P, H2S, or a combination thereof.

[0012] In some embodiments, the step of growing a solid hydride material includes depositing its components by molecular beam epitaxy.

[0013] In another embodiment, the solid hydride material comprises a host-guest structure. In some embodiments, the guest component of the host-guest structure comprises a sulfur hydride, a carbon hydride, or a combination thereof. In some embodiments, the host component of the host-guest structure comprises Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, La, or a combination thereof.

[0014] In some embodiments, the solid hydride material exhibits superconductivity at a first combination of a first temperature and a first pressure when there is no strain. In another embodiment, the solid hydride material exhibits superconductivity at a second combination of a second temperature and a second pressure when there is strain, where the second temperature is higher than the first temperature, the second pressure is lower than the first pressure, or both.

[0015] In some embodiments, the solid hydride material has an Im-3m cubic or Cmcm orthorhombic structure. In some embodiments, a set of lattice parameters of the growth surface are symmetric with respect to the crystal structure of the solid hydride material.

[0016] In some embodiments, strain reduces the interatomic spacing within the solid hydride material. In some embodiments, the interatomic spacing is the hydrogen spacing. In some embodiments, the hydrogen spacing is 1.1 to 1.3 Å.

[0017] In some embodiments, the solid hydride material comprises a component covalently bonded to hydrogen and having a coordination number of at least 6. In some embodiments, the solid hydride material comprises a covalently bonded metal hydride. In another embodiment, the solid hydride material has a higher hydrogen content compared to the maximum possible content determined by the formal oxidation state of the constituent elements of the solid under ambient conditions without strain. [Brief explanation of the drawing]

[0018] [Figure 1]A representative schematic diagram of a superconducting structure including a solid hydride material and a crystalline substrate according to an embodiment of the present disclosure. [Figure 2] A representative schematic diagram showing the strain induced by the crystal lattice mismatch between the solid hydride material and the substrate according to an embodiment of the present disclosure. [Figure 3] A representative schematic diagram of an MBE chamber having an effusion cell for various species used in the fabrication of a solid hydride material according to an embodiment of the present disclosure. [Figure 4] A diagram showing the crystal structure of an exemplary solid hydride material according to an embodiment of the present disclosure. [Figure 5] A flowchart showing a method of fabricating a superconducting material according to an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0019] The present disclosure may be embodied in various forms, but the following description of some embodiments is made on the understanding that the present disclosure should be regarded as an exemplification of the invention and is not intended to limit the invention to the specific embodiments shown.

[0020] The use of numerical values ​​in the various quantitative values ​​specified in this application is indicated as approximations, as if the word “approximately” were placed before both the minimum and maximum values ​​within the indicated range, unless otherwise explicitly specified. It should be understood that, although not necessarily explicitly stated, the term “approximately” is placed before all numerical representations. Such range formats are used for convenience and brevity and should be understood flexibly to include not only the numerical values ​​explicitly designated as limits of the range, but also all individual numerical values ​​or subranges encompassed within that range, to the same extent as each numerical value and subrange is explicitly designated. For example, a ratio within the range of approximately 1 to approximately 200 should be understood to include not only the explicitly listed limits of approximately 1 and approximately 200, but also individual ratios, e.g., approximately 2, approximately 3, and approximately 4, as well as subranges, e.g., approximately 10 to approximately 50, approximately 20 to approximately 100, etc. Furthermore, the disclosure of ranges is intended as a continuous range encompassing all values ​​between the listed minimum and maximum values ​​and any range that can be formed by such values.

[0021] One of the long-standing challenges in experimental physics is the observation of room-temperature superconductivity (RTSC). In the last decade, there has been a resurgence in the discovery of materials for room-temperature superconductivity, and it has been proven that extreme pressure is the most common ordering parameter for room-temperature superconductivity, which facilitates the creation of new quantum materials with intrinsic stoichiometry and pressure-induced metallization mechanisms. See Bi, T., Zarifi, N., Terpstra, T., and Zurek, E. The Search for Superconductivity in High Pressure Hydrides, Reference Module in Chemistry, Molecular Sciences and Chemical Engineering (Elsevier, 2019) doi:10.1016 / B978-0-12-409547-2.11435-0; and Pickard, CJ, Errea, I, and Eremets, MI Superconducting Hydrides Under Pressure, Annu. Rev. Condens. Matter Phys. 11, 57-76 (2020).

[0022] One of the most important discoveries in achieving RTSC is the pressure-induced disproportionation of hydrogen sulfide (H2S) to H3S at 155 gigapascals and 203 Kelvin. c This has been confirmed (Drozdov 1). The synthesis of superhydrides at reduced pressures (e.g., significantly lower than 155 gigapascals) will enable transformative technologies ranging from energy transport to quantum computing.

[0023] This specification provides superconducting materials (e.g., superhydrides) and methods for producing them that can achieve superconductivity at commercially relevant pressures and temperatures. The methods and materials may utilize epitaxial strain due to lattice mismatch between a solid hydride material and a corresponding crystalline substrate on which they are formed and which reduces the pressure (e.g., mechanically applied by a diamond anvil cell (DAC)) at which one or both materials exhibit superconductivity.

[0024] In some embodiments, the method includes the step of providing a crystalline substrate including a growth surface, the growth surface having a set of lattice parameters (e.g., one-dimensional, two-dimensional, or three-dimensional lattice constants and lattice vectors defining angles between them). In some embodiments, the set of lattice parameters of the growth surface is symmetric with respect to the crystal structure of the solid hydride material. The crystalline substrate is designed to have a somewhat frustrated lattice (e.g., the same or similar space group and symmetry as the grown superconducting material). For example, if the desired final space group of the superconducting material is Im-3m or Cmcm, the substrate has the same space group, but its lattice parameters (e.g., one or more lattice constants) are different from those of the superconducting material. The difference in lattice parameters between the substrate and the superconducting material creates a chemical pressure that reduces the interatomic (e.g., between hydrogens) spacing within the superconducting material, and therefore reduces the pressure at which the superconducting material exhibits superconductivity.

[0025] In some embodiments, the method further includes the step of growing a solid hydride material (e.g., a host-guest material, an encapsulated compound, or an inclusion compound) on a growth surface of a substrate. Figure 1 shows one such host-guest structure grown on a substrate surface according to an embodiment of the present disclosure. In some embodiments, a set of lattice parameters of the substrate are selected by chemically conditioning the substrate (e.g., by substitution or interstitial doping) such that the solid hydride material is subjected to a strain that reduces the applied pressure (e.g., mechanical pressure) at which the solid hydride material exhibits superconductivity.

[0026] According to one aspect of this disclosure, the strain imparted to a grown solid hydride material arises from a mismatch in the lattice parameters of the solid hydride material and the crystalline substrate, as shown in Figure 2. As can be seen by referring to Figure 2, when the lattices of the solid hydride material and the substrate are matched, there is no strain and the interatomic spacing of the solid hydride material does not change. However, if there is a lattice mismatch between the solid hydride material and the substrate, the mismatch generates strain that reduces the interatomic spacing of the components (e.g., hydrogen) of the solid hydride material.

[0027] In some embodiments, the desired final space group of the superconducting material may be Im-3m or Cmcm. Therefore, in some embodiments, the crystal system of the superconducting material is orthorhombic (e.g., a set of lattice parameters including three intrinsic lattice constants in each of three mutually orthogonal directions) or cubic (e.g., a set of lattice parameters including a single equal lattice constant in each of three mutually orthogonal directions). In other embodiments, the desired final space group of the superconducting material is

[0028]

number

[0029] In some embodiments, the lattice mismatch between the solid hydride material and the substrate may be in the range of about 1% to about 20%. For example, the lattice mismatch between the solid hydride material and the substrate may be about 1%, about 5%, about 10%, about 15%, or about 20%. According to various aspects of this disclosure, the lattice mismatch may include mismatches between any of the three lattice constants a, b, or c, any of the three lattice vectors α, β, or γ, or any combination thereof. As will be readily apparent to those skilled in the art, a larger lattice mismatch between the substrate and the solid hydride material can impart a greater degree of strain, and therefore a greater reduction in the interatomic spacing of the solid hydride material grown on the substrate. Naturally, as will also be readily apparent to those skilled in the art, if the lattice mismatch is excessively large, the difficulty of forming one lattice onto another can increase, and therefore the degree of lattice mismatch selected represents a compromise between increased strain in the solid hydride material (and thus lower applied pressure at which it exhibits superconductivity) and increased difficulty in manufacturing. Furthermore, depending on the material of the solid hydride, the change in interatomic spacing may not be linearly proportional to lattice mismatch, and therefore excessively large lattice mismatch may begin to increase rather than continue to decrease the interatomic spacing of the solid hydride material. Thus, the optimization of lattice mismatch is material-dependent, as will be readily apparent to those skilled in the art.

[0030] In addition to, or instead of, lattice mismatches in lattice parameters, in some embodiments, lattice mismatches between a solid hydride material and a substrate may be provided by mismatches in the space groups of the substrate and the solid hydride material, mismatches in symmetry operators between them, or a combination thereof. Furthermore, in addition to, or instead of, mismatches in lattice parameters, space groups, and symmetry operators, in some embodiments, lattice mismatches between a solid hydride material and a substrate may be provided by rotational misalignments between the lattices of the substrate and the lattices of the solid hydride material. For example, the lattices of the substrate and the solid hydride material may rotate relative to each other by an amount in the range of about 1° to about 20°. While we do not wish to be bound by theory, it is thought that this rotational misalignment provides a torque-type strain that can reduce the interatomic (e.g., between hydrogen atoms) spacing of the solid hydride material.

[0031] In some embodiments, the solid hydride material and the substrate each have an Im-3m space group and lattice mismatch of about 1% to about 20%. For example, the lattice mismatch between the solid hydride material and the substrate is about 1%, about 5%, about 10%, about 15%, or about 20%. In other embodiments, the solid hydride material and the substrate each have a Cmcm space group and lattice mismatch of about 1% to about 20%. For example, the lattice mismatch between the solid hydride material and the substrate is about 1%, about 5%, about 10%, about 15%, or about 20%.

[0032] In some embodiments, the solid hydride material and the crystalline substrate have different lattice constants. In these embodiments, the lattice constants of the solid hydride material and the crystalline substrate may differ by about 1% to about 20%. For example, in some embodiments, the lattice constant of the crystalline substrate is smaller than that of the solid hydride material, which can generate compressive strain within the solid hydride material. In these embodiments, the lattice mismatch can generate compressive lattice mismatch strain that can reduce one or more lattice constants of the solid hydride material by about 1% to about 35% (for example, by an amount roughly equal to a difference of plus or minus 15% in lattice constants). As a further example, in other embodiments, the lattice constant of the crystalline substrate is larger than that of the solid hydride material, which can generate tensile strain within the solid hydride material. In these embodiments, the lattice mismatch can generate tensile lattice mismatch strain that can increase one or more lattice constants of the solid hydride material by about 1% to about 35% (for example, by an amount roughly equal to a difference of plus or minus 15% in lattice constants).

[0033] In some embodiments, lattice mismatch can reduce the interatomic (e.g., between hydrogen atoms) spacing of a solid hydride material, and thus impart sufficient strain to the solid hydride material to reduce the pressure at which a superconducting material exhibits superconductivity. For example, in some embodiments, a difference in lattice parameters up to about 20% can result in a reduction of interatomic spacing in the solid hydride material by up to 80% (e.g., about 80%, about 60%, about 50%, about 40%, about 30%, about 20%, or about 10%). As will be readily apparent to those skilled in the art, the relationship between lattice mismatch strain and compression is not linear but rather described by a polynomial function.

[0034] In some embodiments, lattice mismatch can impart sufficient strain to a solid hydride material to enable superconductivity at pressures below 180 gigapascals (GPa). For example, in some embodiments, lattice mismatch can impart sufficient strain to a solid hydride material to enable superconductivity at pressures below about 180 GPa, below about 150 GPa, below about 100 GPa, below about 75 GPa, and below about 50 GPa. In some embodiments, lattice mismatch can impart sufficient strain to a solid hydride material to enable superconductivity at pressures below about 30 GPa (e.g., below which superconducting devices can be offered outside of laboratory environments), below about 10 GPa (e.g., below which superconducting devices can be offered at a commercially viable cost and complexity level), below about 2 GPa (e.g., below which superconducting devices can be offered cost-effectively on a very large scale), below atmospheric pressure, or even in a vacuum environment.

[0035] In some embodiments, pressure can be applied to a solid hydride material by mechanical pressure. For example, a superconducting material may be placed in a DAC and compressed between opposing culets. In some embodiments, a pressure transfer medium (e.g., argon, xenon, hydrogen, helium, methanol, ethanol, paraffin oil, etc., or some combination thereof) may be contained within a diamond anvil cell to convert the uniaxial pressure supplied by the DAC into a uniform hydrostatic pressure. As will be readily apparent to those skilled in the art, lower operating pressures allow the use of DACs with larger sample sizes, and thus, if lattice mismatch can impart sufficient strain to allow the solid hydride material to exhibit superconductivity at lower pressures, larger devices containing superconducting materials, such as millimeter- or even centimeter-scale quantum processors, may be operated in the DAC. In other embodiments, other devices for applying mechanical pressure may also be used, including other anvil presses containing less expensive anvil materials than diamond (e.g., metals).

[0036] In some embodiments, the solid hydride material exhibits superconductivity at increased temperatures above about 150 Kelvin (K). For example, in some embodiments, the solid hydride material exhibits superconductivity at increased temperatures of about 150 K, about 175 K, about 200 K, about 225 K, about 250 K, about 260 K, about 270 K, or about 280 K.

[0037] In some embodiments, the solid hydride material exhibits superconductivity at reduced pressure and increased temperature. In some embodiments, the solid hydride material exhibits superconductivity at ambient pressure and temperature. In some embodiments, the solid hydride material exhibits superconductivity at reduced pressure and increased temperature, with the reduced pressure being less than approximately 180 GPa and the increased temperature being greater than approximately 260 K.

[0038] In some embodiments, the solid hydride material is a host-guest structure comprising a guest component and a host component. In some embodiments, the guest component comprises a sulfur hydride, a carbon hydride, or a combination thereof. In some embodiments, the host component comprises lithium (Li), boron (B), beryllium (Be), or a combination thereof. While we do not wish to be bound by theory, the presence of lighter atoms such as Li, B, and Be is thought to aid in the electron-phonon coupling mechanism and phonon-mediated superconductivity. In some embodiments, the host component comprises magnesium (Mg), manganese (Mn), iron (Fe), scandium (Sc), yttrium (Y), or a combination thereof. While we do not wish to be bound by theory, the presence of Mg, Mn, Fe, Sc, and Y is thought to allow for greater intercalation of hydrogen into the host-guest structure at relatively low pressures. In some embodiments, the host component comprises nitrogen (N), selenium (Se), phosphorus (P), or a combination thereof. While we do not wish to be bound by theory, the presence of N, Se, and P is thought to make lone pairs available to donate to the sigma* bond of H2, inducing bond dissociation (decreasing bond order). In some embodiments, the host component includes Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, La, or any combination thereof. In some embodiments, the superconducting material may be an inclusion or encapsulation compound comprising a lattice or framework of a hydrogen-containing material and one or more guest components including Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, La, or any combination thereof.

[0039] In some embodiments, the method includes the step of providing a crystalline substrate by growing a diamond structure by chemical vapor deposition. Different crystal orientations of diamond allow for the use of a range of lattice parameters for use as a substrate. In embodiments where an undoped diamond crystal is used as the substrate, the lattice parameters may be a=b=c=3.567 Å and α=β=γ=90°. In embodiments where the diamond crystal is doped to adjust its lattice parameters, the lattice constants may be about 3 Å to 5 Å. In other embodiments using a crystalline substrate, the lattice constants (for the basic unit cell) may be about 2.5 Å to about 10 Å. In some embodiments, the growth surface is parallel to the (110) lattice plane of the diamond structure. In other embodiments, the growth surface is parallel to the (121) lattice plane of the diamond structure.

[0040] In some embodiments, the method further includes replacing carbon atoms in a diamond structure with other materials (e.g., atoms or molecules of other elements) by substitution doping to provide a substrate having desired lattice parameters and / or providing an additional hydrogen source for a superconducting material. In some embodiments, the other materials include boron (B), sulfur (S), phosphorus (P), hydrogen sulfide (H2S), or combinations thereof. In some embodiments, the step of replacing carbon atoms includes focused ion beam deposition of B, S, P, H2S, or combinations thereof.

[0041] In some embodiments, the method further includes the step of adjusting the lattice parameters of the diamond structure with interstitial dopants (e.g., atoms or molecules of elements other than carbon). In some embodiments, the other material includes hydrogen (H), fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), flerovium (Fl), or any combination thereof. In some embodiments, interstitial doping of the diamond structure with the other material includes focused ion beam deposition.

[0042] In some embodiments, substitution doping, which replaces carbon atoms in the diamond structure with other materials, allows for fine-tuning of the lattice parameters at the growth surface of the substrate. For example, substitution doping with materials larger than carbon, such as sulfur or phosphorus, can increase one or more lattice constants at the growth surface, while substitution doping with materials smaller than carbon, such as boron, can decrease one or more lattice constants at the growth surface. In some embodiments, interstitial doping can further fine-tune the lattice parameters at the growth surface of the substrate (for example, by increasing or decreasing one or more lattice constants at the growth surface).

[0043] In some embodiments, the method further includes the step of tuning the lattice parameters of a diamond structure having vacancies. For example, by colliding carbon atoms with the crystal structure, other carbon atoms in the crystal lattice can be removed from their positions, leaving vacancies at those sites, thereby reducing one or more lattice constants in the region of the vacancies. As will be readily apparent to those skilled in the art, other methods can also be used to introduce vacancies into the crystal lattice to tune the lattice parameters, whether they be carbon or any other material.

[0044] In some embodiments, the amount of vacancies, substitutions, or interstitial dopants may be selected to provide desired lattice parameters on the growth surface. In this regard, the amount of dopants may be low (e.g., on the order of about 1 dopant per 1,000,000 to 100,000,000 carbon atoms), high doping (e.g., on the order of about 1 dopant per 10,000 to 1,000,000 carbon atoms), or very high doping (e.g., more than 1 dopant per 10,000 carbon atoms).

[0045] In some embodiments, the dopant may be provided on the growth surface (e.g., in a portion of the crystal lattice adjacent to the grown solid hydride material). In other embodiments, the dopant may extend to deeper levels within the crystal lattice, or even through the bulk of the substrate material. In some embodiments, the dopant concentration may be constant, while in other embodiments, the dopant concentration may vary with respect to the distance from the growth surface (e.g., providing a lattice constant that varies with depth).

[0046] In some embodiments, the growth surface may be patterned or textured (e.g., using known lithography techniques) to promote the growth of the solid hydride material in a desired orientation, to improve the regularity of the crystal lattice of the solid hydride material, or to otherwise enhance desired properties in the grown solid hydride material.

[0047] In the exemplary embodiments described above, the substrate is described and illustrated as a diamond crystal structure grown by CVD and optionally doped by focused ion beam deposition; however, in other embodiments, other substrate materials formed by different processes may also be used. For example, in some embodiments, other substrates, such as graphene, graphane, silicon, silicon derivatives, or any combination thereof, may be used instead of diamond, so as to take advantage of various tunable lattice parameters by doping that enable the production of solid hydrides exhibiting superconductivity at desired combinations of temperature and pressure. Furthermore, binary crystals, such as silicon carbide, may be used as substrates, and in some embodiments, as described in more detail above, may be provided by replacing a significant proportion of carbon atoms in the diamond crystal structure (e.g., 1 / 4, 1 / 3, 1 / 2, 2 / 3, 3 / 4, etc.) by focused ion beam deposition. According to some embodiments, diamond and other crystals may be formed by processes other than CVD (e.g., by high-pressure high-temperature synthesis, by crystal melting, by Czochralski method, by various lamination processes, "Scotch Tape method", atomic layer deposition (ALD), physical vapor deposition (PVD), sputtering, or any combination thereof). According to some embodiments, substitution and interstitial doping of diamond and other crystals may be carried out by processes other than focused ion beam deposition (e.g., by various reaction chemical methods including PVD, MBE, bore milling, laser heating, high-volume pressing, etc., or any combination thereof).

[0048] In some embodiments, the step of growing a solid hydride material includes separately depositing its components by MBE. Figure 3 shows an exemplary MBE chamber in which the components of the solid hydride material are contained within efusion cells 1-n. The components of the solid hydride material are vaporized within the efusion cells and guided toward a desired location on the growth surface of the substrate, where the solid hydride material is grown. In some embodiments, additional efusion cells containing doping species used to replace carbon atoms in the diamond structure or to add interstitial dopants to the diamond structure may also be used.

[0049] In some embodiments, growing solid hydride materials by MBE may involve guiding the components of the solid hydride material to desired locations on the growth surface based on the desired crystal structure of the solid hydride material. For example, to produce a two-dimensional or three-dimensional crystal structure by MBE, single materials (e.g., a single atom or a single molecule) emitted by an effusion cell may be accumulated at specific site locations within the growth crystal lattice in a manner similar to known nanoassembly methods. In some embodiments, a three-dimensional crystal lattice may be constructed from multiple stacked two-dimensional crystal layers. (See Wofford, J., Nakhaie, S., Krause, T., et al., A hybrid MBE-based growth method for large-area synthesis of stacked hexagonal boron nitride / graphene heterostructures, Sci Rep 7, 43644 (2017), doi:10.1038 / srep43644) ("Wofford"). In such embodiments, deposition may occur layer by layer, but interlayer interactions between heterogeneous layers may provide a mechanism for three-dimensional nanoassemblies.(Xiang Yuan, Lei Tang, Shanshan Liu, Peng Wang, Zhigang Chen, Cheng Zhang, Yanwen Liu, Weiyi Wang, Yichao Zou, Cong Liu, Nan Guo, Jin Zou, Peng Zhou, Weida Hu, and Faxian Xiu, Arrayed van der Waals Vertical Heterostructures Based on 2D GaSe Grown by Molecular Beam Epitaxy, Nano Lett. 2015, 15 (5) 3571~3577, doi: / 10.1021 / acs.nanolett.5b01058;Bongjoong Kim, Jiyeon Jeon, Yue Zhang, Dae Seung Wie, Jehwan Hwang, Sang Jun Lee, Dennis E. Walker Jr., Don C. Abeysinghe, Augustine Urbas, Baoxing See Xu, Zahyun Ku, and Chi Hwan Lee, Deterministic Nanoassembly of Quasi-Three-Dimensional Plasmonic Nanoarrays with Arbitrary Substrate Materials and Structures, Nano Letters 2019 19 (8), 5796~5805, doi:10.1021 / acs.nanolett.9b02598.

[0050] Alternatively, or additionally, one or more three-dimensional islands may form sites around which three-dimensional crystals can be constructed. In some embodiments, the nanoassembly method described above can be used to provide a 3D electronic band structure (e.g., within a periodic network or between deposited layers). In some embodiments, multiple stacked two-dimensional crystalline layers are bonded by van der Waals interactions to form a van der Waals heterostructure of the solid hydride material. In these and other embodiments, reflection fast electron diffraction (RHEED) can be used to monitor the growth of the crystalline layers.

[0051] In some embodiments, the method further includes the step of using MBE to initiate a reaction between hydrogen and two or more different materials (having one or more constituent elements) in order to form a plurality of molecules, each containing a hydrogen portion and at least one of the constituent elements from one of the different materials. In the example of two different molecules, the plurality of molecules include a first molecule having a first composition and a second molecule having a second composition.

[0052] In some embodiments, the hydrogen in the solid hydride material may be provided in various forms or various hydrogen precursors. Exemplary hydrogen precursors include, but are not limited to, atomic hydrogen, molecular hydrogen, hydrogen polymers, or polyhydrides. More specific hydrogen precursors include, but are not limited to, methane, HS, silane, LiH, or any hydrogen precursor used in molecular beam epitaxy or chemical vapor deposition (e.g., gaseous hydrogen precursors). In some embodiments, the solid hydride material has a higher hydrogen content compared to the maximum possible content determined by the formal oxidation state of the constituent elements of the solid under ambient conditions without strain.

[0053] While hydrogen is referred to in the various exemplary embodiments described herein, those skilled in the art will understand that any of the isotopes of hydrogen (e.g., protium, deuterium, or tritium) may be used in combination or individually as substitutes for each other. Therefore, whenever “hydrogen” is referred to herein, it should be understood that any of these hydrogens is intended.

[0054] In some embodiments, the method includes the step of selecting two or more different materials, each containing one or more constituent elements. Exemplary constituent elements include, but are not limited to, those selected from H, S, Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, or La. The materials may be selected for their properties as stabilizers, pressurizers, or chemical dopants as described herein.

[0055] In some embodiments, the solid hydride material exhibits superconductivity at a first combination of a first temperature and a first pressure when there is no strain. In some embodiments, the solid hydride material exhibits superconductivity at a second combination of a second temperature and a second pressure when there is strain, where the second temperature is higher than the first temperature, the second pressure is lower than the first pressure, or both.

[0056] In some embodiments, the solid hydride material comprises at least three different elements, including hydrogen, and exhibits superconductivity at pressures less than about 180 GPa. In some embodiments, the host-guest structure is compound XH x +YH y Formed from a combination of +H2, where X is selected from Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, and / or La, and Y is selected from Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, and / or La, and x and y are stoichiometric amounts of the compound containing X and Y, respectively. In some embodiments, the solid hydride material is a carbonaceous sulfur hydride.

[0057] In some embodiments, the solid hydride material comprises at least four different elements, including hydrogen, and exhibits superconductivity at pressures less than about 180 GPa. In some embodiments, the solid hydride material comprises compound XH x +YH y +ZH z Formed from combinations of +H2, where X is selected from Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, and / or La; Y is selected from Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, and / or La; Z is selected from Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, and / or La; and x, y, and z are stoichiometric or nonstoichiometric amounts of the compound containing X, Y, and Z, respectively.

[0058] In yet another embodiment, the solid hydride material comprises a first component A containing a hydrogen-containing component containing hydrogen; a second component B and a third component C, and the solid hydride has the formula A a B b C c H x where b:c is in the range of 1:20 to 20:1, a:b is in the range of 1:20 to 20:1, x is in the range of 1 to 15, H is hydrogen, C may be H with x = 0 in a ternary system, C is different from H in a quaternary system, and one or more of A, B, C are undoped or have a dopant concentration in the range of about 0% to 20%.

[0059] In some embodiments, the solid hydride material is a metal crystal containing metal or carbon, sulfur, and hydrogen. In yet another embodiment, the solid hydride material is a metal crystal or is formed from a composition having the formula (H2S) 2-x (CH4) x H2 or is formed from a combination of compounds XH x +YH y +ZH z +H2, where XH x is methane and YH y is H2S. In some embodiments, the solid hydride material contains a component that covalently bonds to hydrogen and has a coordination number of at least 6. In some embodiments, the solid hydride contains a covalent metal hydride.

[0060] In yet another embodiment, the solid hydride material is a host-guest structure containing a guest component and a host component, the guest component contains hydrogen, and the host component contains at least one of a stabilizer that promotes the bonding of hydrogen to the host component and / or the formation of a different network containing at least some of the hydrogen, or a pressurizing agent that applies chemical pressure to the periodic lattice of the host-guest structure to reduce the interatomic spacing in the periodic lattice.

[0061] In some embodiments, the solid hydride material has reduced interatomic spacing between hydrogen atoms or dimers. Figure 4 shows an exemplary structure of a superconducting material produced according to the method of the present disclosure, comprising carbon, hydrogen, and sulfur. This structure comprises carbon and sulfur arranged periodically in a three-dimensional motif. In one or more embodiments, the sulfur is arranged in a Cmcm symmetric motif, and the overall structure is an Im-3m structure.

[0062] In some embodiments, sulfur and carbon may be substituted with different elements. In some embodiments, the structure includes stabilizers (e.g., carbon, sulfur, or substitutes for carbon or sulfur) that promote the bonding of hydrogen to the surrounding lattice and / or the formation of different networks containing at least some hydrogen, or pressurizers (e.g., carbon, sulfur, or substitutes for carbon or sulfur) that apply chemical pressure to the periodic lattice to reduce the interatomic spacing within the lattice.

[0063] In some embodiments, the stabilizer comprises a chemical component (including molecules or atoms) comprising at least one of Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, or La. An exemplary pressurizer comprises a chemical component (e.g., atoms or molecules) comprising at least one of Li, B, Be, Mg, Mn, Fe, Sc, Se, P, Y, or La. In various embodiments, the chemical component constitutes both the stabilizer and the pressurizer. The stabilizer and pressurizer can also be considered as chemical dopants.

[0064] Figure 4 further illustrates an example where the interatomic distance between hydrogen atoms or dimers in a solid hydride material is in the range of 1.1–1.3 angstroms (similar to, for example, those found in metallic hydrogen). Hydrogen atoms can form molecular hydrogen (dimers or covalently bonded hydrogen pairs), and the sigma bond within hydrogen weakens as the bond order is reduced from 2 to possibly about 1.5. In other embodiments, the bond order can be reduced to zero so that hydrogen atoms in the solid hydride material contain atomic hydrogen. As used herein, bond order is the number of chemical bonds between pairs of atoms and indicates the stability of the bond. For example, diatomic hydrogen (hydrogen dimer, HH) has a bond order of 2, and atomic hydrogen has a bond order of 0. The interatomic distance in the range of 1.1–1.3 angstroms may also be the distance between hydrogen atoms within a dimer and / or between adjacent hydrogen atoms or hydrogen dimers.

[0065] In further embodiments, hydrogen in a solid hydride material can be considered to include hydrogen atoms or dimers that form covalent bonds (e.g., directional bonds) with other adjacent hydrogen atoms or dimers as a result of hydrogen atoms or dimers sharing and overlapping electrons among themselves, or as a result of hybridization of two or more atomic orbitals. In further embodiments, hydrogen atoms or hydrogen dimers interact with their neighbors in the solid hydride material by resonance bonding (e.g., similar to resonance bonding in benzene). In one or more embodiments, the hydrogen arranged in the solid hydride material constitutes a self-interacting hydrogen-rich network. In some embodiments, the solid hydride material comprises a framework defining channels, each channel containing a series of hydrogen atoms or hydrogen dimers located along each length of the channel.

[0066] Figure 4 further illustrates an exemplary host-guest structure comprising a host component and a guest component, wherein at least one of the host component or guest component comprises a periodic lattice, and the guest component comprises hydrogen. The host component comprises at least one stabilizer that facilitates the bonding of hydrogen to the host component and / or the formation of different networks comprising at least some hydrogens, or a pressurizer that applies chemical pressure to the periodic lattice to reduce the interatomic spacing within the lattice. In some embodiments, the method comprises the step of dissociating molecular hydrogen from the host-guest structure to allow the introduction of inert atoms into a van der Waals-like printed lattice. In some embodiments, palladium (Pd) may enable the dissociation of molecular hydrogen.

[0067] Figure 4 further illustrates examples where the solid hydride material is a host-guest structure comprising a hydrogen network, a hydrogen framework, or a hydrogen-containing channel or pore. The channel or pore (e.g., a one-dimensional pore or one-dimensional channel) contains a series of hydrogen atoms or hydrogen dimers (molecular hydrogen) located along the length of the channel. In various embodiments, the distance between adjacent hydrogen atoms or dimers within the channel is in the range of 1.1 angstroms to 1.3 angstroms. In various embodiments, the channel or network comprises one or more fibrous structures, one or more filamentous structures, or other structures whose length is substantially (e.g., at least 1000 times) longer than its width. The channel is defined by a surrounding lattice of chemical components (stabilizers and / or pressurizers) distinct from the hydrogen network. In various embodiments, the lattice, framework, or matrix (e.g., including chemical components, e.g., stabilizers or pressurizers) contains or retains hydrogen and provides a chemical environment for hydrogen that enables higher Tc at lower pressures. Figure 4 shows an example where the stabilizers and / or pressurizers include chemical components containing carbon and sulfur. However, other chemical components (e.g., stabilizers and pressurizers) may be used as illustrated herein.

[0068] In one or more embodiments, the superconductor comprises a solid hydride material comprising a first component A; a second component B and a third component C, wherein the solid hydride is of formula A a B b C c H x The formula has the following characteristics, where H is C in the ternary compound, C is different from H in the quaternary compound, b:c is in the range of 1:20 to 20:1, a:b is in the range of 1:20 to 20:1, x is in the range of 1 to 15, and A, B, or C are independently selected from Li, B, Be, Mg, Mn, Fe, Sc, N, Se, P, Y, C, S, or La. A, B, or C may be substituted with other elements from the list, or with other elements to reflect doping (e.g., doping with other elements up to 20%).

[0069] Figure 5 is a flowchart of a method 500 for producing a superconducting solid hydride material according to an embodiment of the present disclosure. Method 500 uses molecular beam epitaxy to deposit a crystalline film of solid hydride material on a crystalline substrate. Method 500 includes step 501 of selecting components for forming the solid hydride material. The selected components may be in the gas phase or the liquid phase. The components are then placed in a separate effusion cell within an MBE chamber in step 502. The MBE chamber is in an ultra-high vacuum environment (e.g., <10°C). -9The concentration is maintained at mbar. The efusion cell is equipped with a mechanical shutter that allows control of the amount of each component used to form the solid hydride material. Once placed in the efusion cell, the components are sublimated from a solid state or evaporated from a liquid phase in step 503. In step 504, the gaseous components are then condensed onto a crystalline substrate where they can react with each other. In some embodiments, the substrate is heated to a high temperature (e.g., 300°C to 600°C) to control the mobility of the gaseous components. Once the gaseous components come into contact with the substrate, a number of processes occur in which the components (i.e., adsorbed atoms) grow to form a solid hydride material. Step 505 includes a nucleation process of adsorbed atoms that initiates the crystalline growth of the solid hydride material onto the substrate. The nucleation process 505 may occur on a single-atom step, on a defect, or directly on the surface of the crystalline substrate. In the case of step 506, method 500 includes monitoring the growth of the crystalline solid hydride layer using RHEED. In some embodiments, monitoring crystal growth using RHEED involves generating a diffraction pattern of the crystal. RHEED enables monitoring of material deposition with near-monolayer accuracy.

[0070] Further information relating to one or more embodiments of the present invention can be found in the following publications (and online additional information): Snider, Elliot, Dasenbrock-Gammon, Nathan, McBride, Raymond, Debessai, Mathew, Vindana, Hiranya, Vencatasamy, Lawter, Kevin V., Salamat, Ashkan, and Dias, Ranga, Superconductivity in a Carbonaceous Sulfur Hydride, Nature, 586, 373-377 (14 October 2020) and online additional information available at doi.org / 10.1038 / s41586-020-2801-z. To the extent permitted in the relevant jurisdiction, this document and the relevant online additional information (and other publications cited herein) are incorporated herein by reference in their entirety. The present invention includes the following embodiments. [Section 1] The steps of providing a crystalline substrate including a growth surface having a series of lattice parameters, and Steps to grow a solid hydride material on a growth surface. A method comprising a series of lattice parameters that impart a strain to a solid hydride material that reduces the applied pressure at which the solid hydride material exhibits superconductivity. [Section 2] The method according to item 1, wherein the step of providing a crystalline substrate includes growing a diamond structure by chemical vapor deposition. [Section 3] The method according to claim 2, wherein the growth surface is parallel to the (110) or (121) lattice planes of the diamond structure. [Section 4] The step of providing a crystalline substrate involves boron (B), sulfur (S), phosphorus (P), and hydrogen sulfide (H). 2 The method according to claim 2, further comprising replacing carbon atoms of the grown diamond structure by substitution doping with S, or a combination thereof. [Section 5] Substitution doping is B, S, P, H 2 The method according to item 4, comprising focused ion beam deposition of S or a combination thereof. [Section 6] The method according to item 1, wherein the step of growing a solid hydride material includes depositing its components by molecular beam epitaxy. [Section 7] The method according to item 1, wherein the step of growing a solid hydride material includes depositing its components in stoichiometric quantities by molecular beam epitaxy. [Section 8] The method according to item 1, wherein the step of growing a solid hydride material includes depositing its components in non-stoichiometric quantities by molecular beam epitaxy. [Section 9] The method according to item 1, wherein the solid hydride material includes a host-guest structure. [Section 10] The method according to claim 9, wherein the guest component of the host-guest structure comprises a sulfur hydride, a carbon hydride, or a combination thereof. [Section 11] The method according to claim 9, wherein the host component of the host-guest structure includes lithium (Li), boron (B), beryllium (Be), magnesium (Mg), manganese (Mn), iron (Fe), scandium (Sc), nitrogen (N), selenium (Se), phosphorus (P), yttrium (Y), carbon (C), sulfur (S), lanthanum (La), or a combination thereof. [Section 12] The method according to item 1, wherein a solid hydride material exhibits superconductivity at a first combination of a first temperature and a first pressure when there is no strain. [Section 13] The method according to item 12, wherein a solid hydride material exhibits superconductivity upon strain at a second combination of a second temperature and a second pressure, wherein the second temperature is higher than the first temperature, the second pressure is lower than the first pressure, or both. [Section 14] The method according to item 1, wherein the solid hydride material has an Im-3m cubic or Cmcm orthorhombic structure. [Section 15] The method according to item 14, wherein the set of lattice parameters of the growth surface are symmetric with respect to the crystal structure of the solid hydride material. [Section 16] The method according to item 1, wherein strain reduces the interatomic spacing in a solid hydride material. [Section 17] The method according to item 16, wherein the interatomic spacing is the interhydrogen spacing. [Section 18] The method according to item 17, wherein the interhydrogen spacing is 1.1 Å to 1.3 Å. [Section 19] The method according to claim 1, wherein the solid hydride material comprises a component that is covalently bonded to hydrogen and has a coordination number of at least 6. [Section 20] The method according to item 1, wherein the solid hydride material comprises a covalent metal hydride. [Section 21] The method according to item 1, wherein the solid hydride material has a higher hydrogen content compared to the maximum possible content determined by the formal oxidation state of the constituent elements of the solid under ambient conditions without strain. [Section 22] A superconducting structure prepared by the method described in any one of items 1 to 21. [Section 23] A crystalline substrate including a growth surface having a series of lattice parameters, and Solid hydride material formed on a crystalline substrate A superconducting structure comprising a set of lattice parameters of a crystalline substrate, wherein a set of lattice parameters imparts a strain to the solid hydride material that reduces the applied pressure at which the solid hydride material exhibits superconductivity. [Section 24] The superconducting structure described in item 23, wherein strain reduces the interatomic spacing within the solid hydride material. [Section 25] A superconducting structure as described in item 24, wherein the interatomic spacing is the interhydrogen spacing. [Section 26] A superconducting structure as described in item 25, wherein the interhydrogen spacing is 1.1 Å to 1.3 Å. [Section 27] A superconducting structure according to item 23, wherein the solid hydride material includes a host-guest structure. [Section 28] The superconducting structure according to item 27, wherein the guest component of the host-guest structure comprises a sulfur hydride, a carbon hydride, or a combination thereof. [Section 29] The superconducting structure according to item 27, wherein the host component of the host-guest structure comprises lithium (Li), boron (B), beryllium (Be), magnesium (Mg), manganese (Mn), iron (Fe), scandium (Sc), nitrogen (N), selenium (Se), phosphorus (P), yttrium (Y), carbon (C), sulfur (S), lanthanum (La), or a combination thereof. [Section 30] The superconducting structure according to item 27, wherein the solid hydride material comprises a metal or a metallic crystal containing carbon, sulfur, and hydrogen. [Section 31] The superconducting structure according to item 27, wherein the solid hydride material comprises a component covalently bonded to hydrogen and having at least 6 coordination numbers. [Section 32] The superconducting structure according to item 27, wherein the solid hydride material comprises a covalent metal hydride. [Section 33] The superconducting structure according to item 27, wherein the solid hydride material exhibits superconductivity at a first combination of a first temperature and a first pressure when there is no strain. [Section 34] The superconducting structure according to item 33, wherein a solid hydride material exhibits superconductivity upon strain at a second combination of a second temperature and a second pressure, wherein the second temperature is higher than the first temperature, the second pressure is lower than the first pressure, or both. [Section 35] The superconducting structure according to item 27, wherein the solid hydride material has an Im-3m cubic or Cmcm orthorhombic structure. [Section 36] The superconducting structure described in item 35, wherein a set of lattice parameters of the growth surface are symmetric with respect to the crystal structure of the solid hydride material. [Section 37] The superconducting structure according to item 27, wherein the solid hydride material has a higher hydrogen content compared to the maximum possible content determined by the formal oxidation state of the constituent elements of the solid under ambient conditions without strain. [Section 38] The superconducting structure described in item 27, wherein the crystalline substrate has a diamond structure. [Section 39] The superconducting structure according to item 38, wherein the growth surface is parallel to the (110) or (121) lattice planes of the diamond structure. [Section 40] The carbon atoms in the diamond structure are boron (B), sulfur (S), phosphorus (P), and hydrogen sulfide (H). 2 The superconducting structure described in item 38, which is replaced by substitution doping of S, or a combination thereof. [Section 41] A method for fabricating superconducting materials, A step of providing a substrate using a superconducting structure as described in any one of paragraphs 22 to 40, A step of depositing components of a solid hydride material onto a superconducting structure using chemical vapor deposition. A method that includes this. [Section 42] A quantum computing device having a superconducting structure as described in any one of items 22 to 40.

[0071] From the above, it will be understood that while specific embodiments of the present invention are described herein for illustrative purposes, various modifications can be made without departing from the scope of the invention. Therefore, the present invention is not limited to the appended claims.

Claims

1. The steps of providing a crystalline substrate including a growth surface having a series of lattice parameters, and Step of growing a solid hydride material on the growth surface. A method including, The step of providing the crystalline substrate includes growing a diamond structure by chemical vapor deposition, A method for applying a strain to a solid hydride material that reduces the applied pressure at which the solid hydride material exhibits superconductivity, wherein the aforementioned series of lattice parameters are used.

2. The method according to claim 1, wherein the growth surface is parallel to the (110) lattice plane or (121) lattice plane of the diamond structure.

3. The step of providing the crystalline substrate involves boron (B), sulfur (S), phosphorus (P), and hydrogen sulfide (H). 2 The method according to claim 1, further comprising replacing carbon atoms of the grown diamond structure by substitution doping with S) or a combination thereof.

4. The aforementioned substitution doping involves B, S, P, and H. 2 The method according to claim 3, comprising focused ion beam deposition of S or a combination thereof.

5. The method according to claim 1, wherein the step of growing the solid hydride material includes depositing its components by molecular beam epitaxy.

6. The method according to claim 1, wherein the step of growing the solid hydride material includes depositing its components in stoichiometric quantities by molecular beam epitaxy.

7. The method according to claim 1, wherein the step of growing the solid hydride material includes depositing its components in non-stoichiometric quantities by molecular beam epitaxy.

8. The method according to claim 1, wherein the solid hydride material includes a host-guest structure.

9. The method according to claim 8, wherein the guest component of the host-guest structure comprises a sulfur hydride, a carbon hydride, or a combination thereof.

10. The method according to claim 8, wherein the host component of the host-guest structure includes lithium (Li), boron (B), beryllium (Be), magnesium (Mg), manganese (Mn), iron (Fe), scandium (Sc), nitrogen (N), selenium (Se), phosphorus (P), yttrium (Y), carbon (C), sulfur (S), lanthanum (La), or a combination thereof.

11. The method according to claim 1, wherein the solid hydride material exhibits superconductivity at a first combination of a first temperature and a first pressure when there is no strain.

12. The method according to claim 11, wherein the solid hydride material exhibits superconductivity due to the strain at a second combination of a second temperature and a second pressure, wherein the second temperature is higher than the first temperature, the second pressure is lower than the first pressure, or both.

13. The method according to claim 1, wherein the solid hydride material has an Im-3m cubic or Cmcm orthorhombic structure.

14. The method according to claim 13, wherein the series of lattice parameters of the growth surface are symmetric with respect to the crystal structure of the solid hydride material.

15. The method according to claim 1, wherein the strain reduces the interatomic spacing within the solid hydride material.

16. The method according to claim 15, wherein the interatomic spacing is the interhydrogen spacing.

17. The method according to claim 16, wherein the interhydrogen spacing is 1.1 Å to 1.3 Å.

18. The method according to claim 1, wherein the solid hydride material comprises a component that is covalently bonded to hydrogen and has at least 6 coordination numbers.

19. The method according to claim 1, wherein the solid hydride material includes a covalent metal hydride.

20. The method according to claim 1, wherein the solid hydride material has a higher hydrogen content compared to the maximum possible content determined by the formal oxidation state of the constituent elements of the solid under ambient conditions without strain.

21. A crystalline substrate having a diamond structure and comprising a growth surface having a series of lattice parameters, and Solid hydride material formed on the crystalline substrate A superconducting structure comprising a crystalline substrate, wherein the series of lattice parameters of the crystalline substrate impart a strain to the solid hydride material that reduces the applied pressure at which the solid hydride material exhibits superconductivity.

22. The superconducting structure according to claim 21, wherein the strain reduces the interatomic spacing within the solid hydride material.

23. The superconducting structure according to claim 22, wherein the interatomic spacing is the interhydrogen spacing.

24. The superconducting structure according to claim 23, wherein the inter-hydrogen spacing is 1.1 Å to 1.3 Å.

25. The superconducting structure according to claim 21, wherein the solid hydride material includes a host-guest structure.

26. The superconducting structure according to claim 25, wherein the guest component of the host-guest structure includes a sulfur hydride, a carbon hydride, or a combination thereof.

27. The superconducting structure according to claim 25, wherein the host component of the host-guest structure includes lithium (Li), boron (B), beryllium (Be), magnesium (Mg), manganese (Mn), iron (Fe), scandium (Sc), nitrogen (N), selenium (Se), phosphorus (P), yttrium (Y), carbon (C), sulfur (S), lanthanum (La), or a combination thereof.

28. The superconducting structure according to claim 25, wherein the solid hydride material comprises a metal or a metal crystal containing carbon, sulfur, and hydrogen.

29. The superconducting structure according to claim 25, wherein the solid hydride material includes a component that is covalently bonded to hydrogen and has at least 6 coordination numbers.

30. The superconducting structure according to claim 25, wherein the solid hydride material includes a covalent metal hydride.

31. The superconducting structure according to claim 25, wherein the solid hydride material exhibits superconductivity at a first combination of a first temperature and a first pressure when there is no strain.

32. The superconducting structure according to claim 31, wherein the solid hydride material exhibits superconductivity due to the strain at a second combination of a second temperature and a second pressure, wherein the second temperature is higher than the first temperature, the second pressure is lower than the first pressure, or both.

33. The superconducting structure according to claim 25, wherein the solid hydride material has an Im-3m cubic or Cmcm orthorhombic structure.

34. The superconducting structure according to claim 33, wherein the series of lattice parameters of the growth surface are symmetric with respect to the crystal structure of the solid hydride material.

35. The superconducting structure according to claim 25, wherein the solid hydride material has a higher hydrogen content compared to the maximum possible content determined by the formal oxidation state of the constituent elements of the solid hydride material under ambient conditions without strain.

36. The superconducting structure according to claim 21, wherein the growth surface is parallel to the (110) lattice plane or the (121) lattice plane of the diamond structure.

37. The carbon atoms in the aforementioned diamond structure are boron (B), sulfur (S), phosphorus (P), and hydrogen sulfide (H). 2 The superconducting structure according to claim 21, which is replaced by substitution doping of S, or a combination thereof.

38. A method for fabricating superconducting materials, A step of providing a substrate using the superconducting structure described in any one of claims 21 to 37, A step of depositing components of a solid hydride material onto the superconducting structure using chemical vapor deposition. A method that includes this.

39. A quantum computing apparatus comprising the superconducting structure according to any one of claims 21 to 37.

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