Method for producing one or more NV centres in diamond

Abstract

The invention relates to a method for producing an NV centre in diamond (220), comprising the steps of: a) providing a diamond (220) having a surface (260); b) defining an implantation region (240) in the surface (260) of the diamond (220); c) N-doping the implantation region (240) of the diamonds (220) in order to raise the Fermi level in the implantation region (240) of the diamond (220) to a value of approximately -0.5 eV from the conduction band edge in the band gap of the diamond material of the diamond (220); d) defining an implantation position (230) in the surface (260) of the diamond (220); e) carrying out a second implantation of a nitrogen isotope by means of focused single-ion implantation with an implantation energy of 9.5 keV into the implantation region (240) of the diamond at the implantation position (230); f) heat treating the diamond (220) at more than 800°C. The method has the advantage whereby, in this way, deterministic NV centres can be produced at predetermined positions (230) in the surface (260) of a diamond (220).

Description

[0001] Process for producing one or more NV centers in diamond

[0002] Field of invention

[0003] The invention relates to methods for producing one or more NV centers in diamond.

[0004] State of the art

[0005] The document presented here indicates the following state of the art:

[0006] Saada, D., Joan Adler, and R. Kalish. "Sulfur: A potential donor in diamond." Applied Physics Letters 77.6 (2000): 878-879.

[0007] E. Gheeraert, N. Casanova, A. Tajani, A. Deneuville, E. Bustarret, JA Garrido, CE Nebel, M. Stutzmann, n-Type doping of diamond by sulfur and phosphorus, Diamond and Related Materials, Volume 11, Issues 3-6, 2002, Pages 289-295, ISSN 0925-9635, https: / / doi.org / 10.1016 / S0925- 9635(01)00683-5.

[0008] Lühmann, Tobias, et al. "Coulomb-driven single defect engineering for scalable qubits and spin sensors in diamond." Nature communications 10.1 (2019): 4956.

[0009] Lühmann, Tobias, Jan Meijer, and Sebastien Pezzagna. "Charge-assisted engineering of color centers in diamond." physica status solidi (a) 218.5 (2021): 2000614.

[0010] Becker, S., Lühmann, T., Meijer, J., & Pezzagna, S. (2023). Photoelectrically detected magnetic resonance on sulfur doped NV centers. AIP Advances, 13(3).

[0011] Herzig, T., Luehmann, T., Raecke, P., Scheuner, C., Pezzagna, S., & Meijer, J. (2021). Color center formation by deterministic single ion implantation. In Semiconductors and Semimetals (Vol. 104, pp. 1-30). Elsevier.

[0012] The document DE 10 2024 115 169 A1 describes exemplary pulse sequences for NV center-based quantum computers. The as yet unpublished international patent application PCT / DE2025 / 100132 describes, among other things, a quantum full adder.

[0013] The documents EP 3 990 684 CO and DE 10 2019 117 423 Al describe the increase in yield in the production of NV centers by means of sulfur doping of the diamond substrate.

[0014] The documents DE 10 2020 007 977 B4, DE 10 2020 101 784 B4 and DE 10 2019 120 716 Al each describe a quantum computer with a sulfur doping of the diamond substrate.

[0015] The German patent application DE 10 2020 008 243.2 claims a "scalable quantum computer based on impurity centers in an O-doped environment" (O-doping), whereby the description largely corresponds to that of DE 10 2020 007 977 B4.

[0016] The document DE 10 2015 106 769 Al describes a device for single ion implantation.

[0017] The document DE 10 2020 000 075 Al describes a quantum sensor controlled guitar.

[0018] The document DE 10 2015 106 769 A1 discloses a device for detecting individual charged particles and a system for material processing containing such a device.

[0019] The formation of NV centers is described in detail in Lühmann, Tobias, et al. "Coulomb-driven single defect engineering for scalable qubits and spin sensors in diamond." Nature communications 10.1 (2019): 4956.

[0020] From Dolde, Florian, et al. "Room-temperature entanglement between single defect spins in diamond." Nature Physics 9.3 (2013): 139-143, Dolde, Florian, et al. "High-fidelity spin entanglement using optimal control." Nature communications 5.1 (2014): 3371 and Shagieva, F., et al. "Microwave-assisted cross-polarization of nuclear spin ensembles from optically pumped nitrogen-vacancy centers in diamond." Nano letters 18.6 (2018): 3731-3737 the entanglement of NV centers is known.

[0021] Details of a single ion implantation system are described in the document DE 10 2015 106 769 Al.

[0022] The document presented here also refers to Matsushita, H., Hirose, S., Yagita, T. et al., "Detection of particles in the ion beam." MRS Advances 7, 1509–1514 (2022). https: / / doi.org / 10.1557 / s43580-022-00394-0 and Räcke, P., J. Meijer, and D. Spemann, "Image charge detection of ion bunches using a segmented, cryogenic detector." Journal of Applied Physics 131.20 (2022) regarding the detection of single ions during the implantation process using single-ion implantation systems.

[0023] Task

[0024] The proposal is based on the task of specifying methods for the generation of several quantum registers based on NV centers that are typically isolated from each other, in particular to enable the production of a compact multi-core quantum computer.

[0025] This problem is solved by the independent claims. Further embodiments are the subject of subclaims.

[0026] Solution to the task

[0027] The invention relates to a method 100 for producing an NV center in diamond, comprising the steps:

[0028] • Providing 110 a diamond 220 having a surface 260, wherein the diamond 220 may have a raised Fermi level upon provision (n-doped diamond)

[0029] • Defining 120 an implantation area 240 on the surface 260 of the diamond 220;

[0030] • If 130 the Fermi level is below -2.9eV to -0.5eV from the conduction band edge and / or below -1.2eV to -0.5eV and / or below -0.8eV to -0.5eV from the conduction band edge in the band gap of the diamond material of the diamond, N-doping 140 of the implantation region 240 of the diamond 220 to raise 140 the Fermi level in the implantation region 240 of the diamond 220 to a value between -2.9eV to -0.5eV from the conduction band edge in the band gap of the diamond material of the diamond 220, wherein a Fermi level of -0.5eV from the conduction band edge in the band gap of the diamond material of the diamond 220 lies in the implantation region 240 of the diamond 220 after the n-doping is preferred;

[0031] • Determining 150 an implantation position on the surface of the diamond;

[0032] • Second implantation 160 of one or more nitrogen isotopes, in particular one or more 15 N or 14N nitrogen isotopes, by means of focused single ion implantation and / or by means of focused molecule implantation with an implantation energy of 9.5 keV per implanted nitrogen ion (per nitrogen isotope) into the implantation region 240 of the diamond 220 at the implantation position 230 with a tolerance of + / - 5 keV and / or with a tolerance of + / - 2 keV and / or with a tolerance of + / - 1 keV and / or with a tolerance of + / - 0.5 keV and / or with a tolerance of + / - 0.2 keV and / or with a tolerance of + / - 0.1 keV and / or with a tolerance of + / - 0.05 keV and / or with a tolerance of + / - 0.02 keV and / or with a tolerance of + / - 0.01 keV, wherein 9.5 keV is preferred as the implantation energy per nitrogen atom (per nitrogen isotope) and wherein preferably the implantation energy of the nitrogen atoms (the nitrogen isotopes) is above 4 keV per implanted nitrogen isotope;

[0033] • Second heat treatment 170 of the diamond at 800°C with a tolerance of + / - 80°C and / or with a tolerance of + / - 40°C and / or with a tolerance of + / - 20°C and / or with a tolerance of + / - 10°C and / or with a tolerance of + / - 5°C and / or with a tolerance of + / - 2°C and / or with a tolerance of + / - 1°C and / or with a tolerance of + / - 0.5°C and / or with a tolerance of + / - 0.2°C and / or with a tolerance of + / - 0.1°C and / or with a tolerance of + / - 0.05°C and / or with a tolerance of + / - 0.02°C and / or with a tolerance of + / - 0.01°C, with 800°C being preferred.

[0034] The method 100 is illustrated in Figure 1.

[0035] Method 100 enables the targeted generation of individual NV centers with high spatial resolution and reproducible energy input. Raising the Fermi level in implantation region 240 promotes the formation of desired defect states. This significantly improves the yield of NV centers. Method 100 thus has the advantage that NV centers can be generated deterministically in this way.

[0036] The technical procedure 100 presented here solves the following technical problems

[0037] • Deterministic single ion implantation with a low ion energy of IkeV to lOkeV.

[0038] • High lateral resolution in three dimensions with 3-5nm resolution relative to the surface of the diamond substrate.

[0039] • High alignment capability (alignment accuracy relative to other structures on the diamond surface) of better than 1 nm.

[0040] • Implantation into an insulating material (diamond). For the development of the technical teaching presented here, a modified Raith-Ionline

[0041] implantation device. It had

[0042] • an ion spot size of 3nm, a laser interferometer for positioning the diamond substrate relative to the ion beam with an accuracy of lnm,

[0043] • a single ion detector 80e with a detection probability of 99.9% (neg. false).

[0044] Details of the structure are described in the document DE 102015 106769 Al.

[0045] The document presented here also refers to Matsushita, H., Hirose, S., Yagita, T. et al., "Detection of particles in the ion beam." MRS Advances 7, 1509–1514 (2022). https: / / doi.org / 10.1557 / s43580-022-00394-0 and Räcke, P., J. Meijer, and D. Spemann, "Image charge detection of ion bunches using a segmented, cryogenic detector." Journal of Applied Physics 131.20 (2022).

[0046] In a first variant of the method 100, the second implantation 160 of the nitrogen isotopes, in particular the 15 N or 14 N nitrogen isotopes, by focused molecular implantation of nitrogen-containing molecules that contain the nitrogen isotopes, in particular the 15 N or 14N nitrogen isotopes, with an implantation energy of 9.5 keV + / - 10% per implanted nitrogen isotope with the above tolerances into the implantation region 240 of the diamond 220 at the implantation position 230. This results in a good NV center formation rate. The focused molecule implantation variant enables a particularly gentle and uniform, and above all closely positioned, introduction of several, preferably but not necessarily different, nitrogen isotopes. This improves the formation of NV centers and in particular of NV center pairs while simultaneously minimizing lattice disturbance. The method 100 thus significantly increases the reproducibility and yield of functional NV centers and, above all, of coupleable NV center pairs.

[0047] In a second variant of the method 100, the second implantation 160 of the nitrogen isotopes, in particular the 15 N or 14N nitrogen isotopes, N2 molecules ionized by focused molecular implantation, which contain the nitrogen isotopes, in particular the 15 N or 14 N nitrogen isotopes, with an implantation energy of 9.5 keV + / - 10% per implanted nitrogen isotope (19 keV implantation energy for the N2 molecule) with the above tolerances into the implantation area 240 of the diamond 220 at the implantation position 230. This has the advantage that the NV centers later formed in the diamond material of the diamond 220 by the nitrogen isotopes located close together in the molecule are also spatially close to one another. The implantation of ionized N z- Molecules enables the targeted placement of two spatially closely spaced nitrogen isotopes in the diamond lattice. This favors the subsequent formation of NV centers in close spatial proximity and thus the formation of NV center pairs that can be coupled by dipole-dipole coupling, which is particularly advantageous for applications in quantum entanglement and spin coupling. This variant of method 100 thus contributes to the improved realization of quantum physical effects.

[0048] In a third variant of the method 100, the Fermi level is raised 140 by means of a first implantation 193 of singly positively ionized sulfur atoms (S+), which have an energy level of -0.5 eV from the conduction band edge, as doping atoms (donors) in the diamond material of the diamond 220 in the implantation region 240. This has the advantage that the vacancies are negatively charged during NV center formation, increasing the formation rate of the NV centers and thus of the coupleable NV center pairs, and increasing the probability that the NV centers are negatively charged during subsequent operation. Furthermore, the T2 time of the NV centers increases.

[0049] In a fourth variant of the method 100, the raising 140 of the Fermi level is carried out by means of a first implantation 193 of sulfur atoms by means of ion implantation with an implantation energy of 40 keV per implanted sulfur ion into the implantation region 240 of the diamond 220 with a tolerance of + / - 10 keV and / or with a tolerance of + / - 5 keV and / or with a tolerance of + / - 2 keV and / or with a tolerance of + / - 1 keV and / or with a tolerance of + / - 0.5 keV and / or with a tolerance of + / - 0.2 keV and / or with a tolerance of + / - 0.1 keV and / or with a tolerance of + / - 0.05 keV and / or with a tolerance of + / - 0.02 keV and / or with a tolerance of + / - 0.01 keV, wherein 40 keV is used as the implantation energy of the Sulfur atoms are preferred. This results in a good agreement between the position of the sulfur atoms and that of the nitrogen isotopes.The first implantation of 193 sulfur atoms with a preferred energy of 40 keV achieves targeted doping at the same depth as the nitrogen isotopes. This ensures precise overlap of the sulfur donors with the 230 implantation positions of the 160 nitrogen atoms implanted later in a second implantation step, efficiently raising the Fermi level locally. The spatial correlation improves the NV center formation rate and the charge stability of the NWs.

[0050] Centers. In this fourth variant of the method 100, the method 100 comprises the step of a first heat treatment 195 of the diamond 220 at more than 800°C and / or more than 900°C and / or more than 1000°C and / or more than 1100°C and / or more than 1200°C and / or more than 1300°C following the first implantation 193 of the sulfur. This has the advantage that the sulfur atoms are thereby activated, and the fluorescence caused by the first implantation 193 disappears.

[0051] In a fifth variant of the method 100, the first implantation 193 of the sulfur is carried out with a dose of 10 17 cm -2 + / -20% and / or + / -10% and / or + / -5% and / or + / -2% and / or + / -1%, where a dose of 10 17 cm -2 is preferred. These are the particularly preferred fluence values ​​determined during the development of the invention. The first implantation 193 of sulfur with a dose of 10 17 cm -2ensures that a sufficient number of donors is present in the implantation region 240 to specifically raise the Fermi level. The preferred fluence values ​​determined during the development of the invention enable an optimal doping concentration that supports the formation and stability of negatively charged NV centers and thus increases the efficiency of the overall process.

[0052] In a sixth variant of the method 100, the method steps for the second implantation 160 of the nitrogen isotopes (atomic or molecular) are carried out several times in the method 100 at different implantation positions for each implanted nitrogen atom or implanted nitrogen-containing molecule or implanted N2 molecule. For this purpose, the method 100 preferably comprises a readjustment 180 of the next implantation location by means of an electrostatic, magnetic, electromagnetic, or mechanical device before the next implantation 160. (See Figure 2) Due to the previously described measures for modifying the Fermi level, the nitrogen isotopes then form NV centers with a formation rate of the implanted nitrogen atoms calculated down or up to 100 virtual implanted nitrogen atoms from the virtual 100 implanted nitrogen atoms.

[0053] 80 virtual implanted nitrogen atoms (80% yield) and / or

[0054] 81 to 79 virtual implanted nitrogen atoms (79% to 81% yield) and / or 83 to 77 virtual implanted nitrogen atoms (77% to 83% yield) and / or 86 to 74 virtual implanted nitrogen atoms (74% to 86% yield) and / or 92 to 68 virtual implanted nitrogen atoms (69% to 92% yield) and / or 100 to 60 virtual implanted nitrogen atoms (60% to 100% yield) form an NV center within the diamond, with a yield of >80% being preferred. By repeatedly implanting nitrogen at different implantation positions, a targeted distribution of individual NV center groups within the diamond lattice is achieved. In combination with the targeted Fermi level elevation, this leads to an exceptionally high formation rate of NV centers, preferably over 80%. The variant of method 100 thus enables precise control of the NV center density for applications in quantum technology.The NV center groups can, for example, be controlled as separate quantum processors, which massively facilitates the creation of multi-core quantum computers.

[0055] In a seventh variant of the method 100, the method 100 comprises the repeated execution of the method steps for the second implantation 160 of the nitrogen isotopes (atomic or molecular) at different implantation positions for each implanted nitrogen atom or implanted nitrogen-containing molecule or implanted N2 molecule. For this purpose, the method 100 preferably comprises a readjustment 180 of the next implantation location by means of an electrostatic, magnetic, electromagnetic, or mechanical device before the next implantation 160. Due to the previously described measures for modifying the Fermi level, the nitrogen isotopes then form NV centers with a non-formation rate of the implanted nitrogen atoms, downscaled or upscaled to 100 virtual implanted nitrogen atoms, of 20 virtual implanted nitrogen atoms from the virtual 100 implanted nitrogen atoms (20% loss rate) and / or

[0056] 19 to 21 virtual implanted nitrogen atoms (19% to 21% loss rate) and / or 17 to 23 virtual implanted nitrogen atoms (17% to 23% loss rate) and / or 14 to 26 virtual implanted nitrogen atoms (14% to 26% loss rate) and / or 8 to 32 virtual implanted nitrogen atoms (8% to 32% loss rate) and / or

[0057] 0 to 40 virtual implanted nitrogen atoms (0% to 40% loss rate) do not form any NV centers within the diamond. Repeated nitrogen implantation at various positions, combined with targeted Fermi level elevation, significantly reduces the non-formation rate of NV centers. The loss rate is preferably below

[0058] 20%, which represents a significant increase in yield. This variant of the method 100 improves the reliability of the method 100 and enables the reproducible generation of NV centers and NV center pairs that can be coupled by dipole-dipole coupling with high efficiency. In an eighth variant of the method 100, the second implantation 160 of the nitrogen atoms (nitrogen isotopes) is carried out by means of a single ion implanter or by means of a single molecule implanter with detection 190 of the single ion or the single molecule with a detection probability for the completed implantation of >90% and / or >95% and / or >98% and / or >99% and / or >99.5% and / or >99.7% and / or >99.8% and / or / 99.9%, with a detection probability of >99.9% being preferred. This has the advantage of preventing unwanted multiple implantations. (See Figure 3) The use of a single-ion or

[0059] A single-molecule implanter with a detection probability of over 99.9% ensures that the implantation of each individual nitrogen atom is reliably detected. This prevents unwanted multiple implantations, increasing the precision of the placement of individual NV centers and / or individual NV center pairs. The variant of method 100 thus enables a controlled and deterministic generation of individual NV centers and / or NV center pairs that can be coupled using dipole / dipole coupling.

[0060] In a ninth variant of the method 100, the method for the second implantation 160 of the nitrogen isotopes 210 as a single atom and / or as part of a molecule at at least two different implantation positions 230 in the same implantation region 240, at least a first implantation position 230 and a second implantation position 230 in the implantation region 240, into the diamond substrate 220, wherein the first implantation position 230 is different from the second implantation position 230 and wherein the distances 250 of the implantation positions between two adjacent implantation positions of two adjacent single-ion implanted and / or single-molecule implanted nitrogen atoms are less than 40 nm and / or less than 30 nm and / or less than 20 nm and / or less than 10 nm, preferably 20 nm. This has the advantage thatthat the intended topology of the quantum registers can be produced in a targeted manner. The second implantation 160 of nitrogen isotopes at several closely spaced implantation positions 230 within the same implantation region 240 with spacings 250 of less than 40 nm, preferably 20 nm, enables the targeted arrangement of several NV centers in defined relationships. This variant of the method 100 allows the controlled production of the topology required for quantum registers (in the implantation regions 240). Supports the probability of a possible dipole-dipole coupling of NV centers and thus supports the construction of scalable quantum logic structures in the diamond 220. In a tenth variant of the method 100, the method for the second implantation 160 of the nitrogen isotopes as a single atom and / or as part of a molecule at at least three different implantation positions 230 in the same implantation region 240,at least a first implantation position 230 and a second implantation position 230 and a third implantation position 230 in the implantation region 240, wherein the implantation positions 230 are different from one another and wherein the implantation positions 230 are arranged in a one- or two-dimensional grid with respect to a projection perpendicular to the surface 260 of the diamond 220 onto the plane of the two-dimensional surface 260 of the diamond 220, and wherein the actual implantation positions 230 deviate by less than 5 nm and / or less than 3 nm and / or less than 2 nm and / or less than 1 nm, preferably less than 3 nm, from the ideal grid position of the grid of the implantation positions 230 in the implantation region 240. (See Figure 4) This has the advantage,that the NV centers as quantum bits of the quantum register to be created (in the respective implantation region 240) have approximately the same distance 250 from each other. The second implantation 160 of the nitrogen isotopes in a one- or two-dimensional lattice with a positional deviation of the implantation positions 230 of less than 3 nm from the ideal lattice position of the lattice of implantation positions 230 in the respective implantation region 240 achieves a highly precise arrangement of the NV centers. This makes it possible to position NV centers as quantum bits with a nearly identical distance 250 from each other, thereby enabling coherent interactions in quantum registers (in the respective implantation regions 240) to be specifically controlled.

[0061] In an eleventh variant of the method 100, the real implantation positions 230 of the successfully generated NV centers are arranged in a one-dimensional or two-dimensional grid of the respective implantation positions 230 in the respective implantation region 240, relative to a projection perpendicular to the surface 260 of the diamond 220 onto the plane of the two-dimensional surface 260 of the diamond 220, wherein these real implantation positions 230 of the NV centers deviate by less than 10 nm and / or less than 5 nm and / or less than 2 nm and / or less than 1 nm from the ideal grid position in the respective grid of the respective implantation positions 230 in the respective implantation region 240. (See Figure 4) This has the advantage that the coupling possibilities among the NV centers can be more or less structurally predetermined.By arranging the real implantation positions 230 of the successfully formed NV centers in a one- or two-dimensional lattice in the respective lattice of the respective implantation positions 230 in the respective implantation region 240 with deviations of less than 10 nm, preferably less than 2 nm, from the ideal lattice positions in the respective lattice of the respective implantation positions 230 in the respective implantation region 240, the coupling conditions of the NV centers for dipole-dipole coupling can be specifically specified. This enables defined control of the quantum mechanical interactions, for example, for scalable quantum registers or coupled qubit systems.

[0062] In a twelfth variant of the method 100, the grid of this real position and / or of the implantation positions 230 is a two-dimensional hexagonal grid or a two-dimensional square grid or a two-dimensional rectangular grid or a one-dimensional grid. (See Figure 4) This has the advantage that the coupling options among the NV centers can be more or less predetermined. By forming a one-dimensional or two-dimensional grid as the respective grid of the respective implantation positions 230 in the respective implantation region 240, in particular in a hexagonal, square or rectangular structure, for the implantation positions 230 or real positions of the NV centers and / or NV center pairs, the distances 250 of the respective NV centers or NV center pairs in a respective implantation region 240 from one another and / or the respective arrangement of the respective NV centers orNV center pairs can be specifically specified. This allows for defined control of the coupling possibilities between the NV centers and / or NV center pairs and supports the targeted design of quantum registers with the desired topology within the respective implantation regions 240.

[0063] In a thirteenth variant of the method 100, the method 100 comprises the production of a first lattice of NV centers at first respective implantation positions 230 in a respective implantation region 240 of the diamond 220 and the production of a second lattice of NV centers at second respective implantation positions 230 in this respective implantation region 240 of the diamond 220, wherein the first implantation positions 230 are different from the second implantation positions 230. This enables the production of more complex lattices and more complex lattice unit cells of the respective implantation positions 230 in the respective implantation regions 240. By forming a first and a second lattice of NV centers and / or NV center pairs at respectively different implantation positions 230 in the same implantation region 240, more complex lattice structures and unit cells can be realized.This variant of method 100 enables a targeted generation of multilayered quantum register geometries with extended coupling options between NV centers and thus supports the construction of more complex quantum physical systems.

[0064] In a fourteenth variant of the method 100, the method 100 generates, during the second implantation 160, one or more first nitrogen isotopes, in particular one or more first 15 N or 14N nitrogen isotopes, by means of a first focused single ion implantation and / or by means of a first focused molecule implantation with a first implantation energy of 9.5 keV with typ.+ / - 10% per implanted nitrogen ion (per nitrogen isotope) into an implantation region 240 of the diamond 220 with a first implantation energy, a first grid of implantation positions 230 of first NV centers in the implantation region 240 of the diamond 220 at first implantation positions 230 in the implantation region 240 with a tolerance of + / - 5 keV and / or with a tolerance of + / - 2 keV and / or with a tolerance of + / - 1 keV and / or with a tolerance of + / - 0.5 keV and / or with a tolerance of + / - 0.2 keV and / or with a tolerance of + / - 0.1 keV and / or with a tolerance of + / - 0.05 keV and / or with a tolerance of + / - 0.02 keV and / or with a tolerance of + / - 0.01 keV, wherein a first implantation energy of 9.5keV per implanted first nitrogen isotope is preferred and wherein and wherein preferably the first implantation energy of the first nitrogen atoms is above 4keV per implanted nitrogen isotope.The method 100 generates one or more second nitrogen isotopes, in particular one or more second, during the second implantation 160. 15 N or 14N nitrogen isotopes, by means of a second focused single ion implantation and / or a second first focused molecule implantation with a second implantation energy into the implantation region 240 of the diamond 220 with a second implantation energy, a second lattice of implantation positions 230 of second NV centers in the implantation region 240 of the diamond 220 at second implantation positions 230 in the implantation region 240, wherein the second implantation energy of the first nitrogen atoms is preferably above 4 keV per implanted nitrogen isotope. Preferably, the first implantation positions 230 are different from the second implantation positions 230. This enables the production of more complex lattices and more complex lattice unit cells.By using different implantation energies to form a first and a second lattice from the implantation positions 230 of NV centers and / or pairs of NV centers at different implantation positions 230 in the same implantation region 240, vertically staggered or energetically differentiated lattice structures of implantation positions 230 can be generated. This variant of the method 100 allows the targeted realization of complex lattice unit cells with differentiated quantum physical properties.

[0065] In a fifteenth variant of the method 100, the first lattice of the implantation positions 230 in a respective implantation region 240 is a hexagonal lattice and the second lattice is preferably a hexagonal lattice in each case (see Figure 5). This enables the densest packing of NV centers on the surface 260 of the diamond 220. By forming both the first and the second lattice of the implantation positions 230 within a respective implantation region 240 as a hexagonal lattice, a particularly dense packing of the NV centers and / or NV center pairs in the respective implantation region 240 is achieved. This variant enables an area-efficient arrangement with a minimal distance 250 between adjacent NV centers and / or NV center pairs, which is particularly advantageous for applications with high quantum bit density and strong coupling. It thus supports the implementation of compact quantum registers.

[0066] In a sixteenth variant of the method 100, the first implantation energy is different from the second implantation energy. This enables the production of three-dimensional lattices of the implantation positions 230 of a respective implantation region 240, which are composed of several two-dimensional lattices. Preferably, the first lattice is offset from the second lattice. By using different implantation energies for the first and second lattices, they can be formed at different depths in the diamond 220. This enables the production of staggered, three-dimensional lattice structures of the implantation positions 230 from several two-dimensional planes. The preferred offset of the lattices facilitates the targeted coupling between NV centers and / or NV center pairs of different planes and supports complex quantum architectures.

[0067] In a seventeenth variant of the method 100, the NV centers of the first lattice of the implantation positions 230 of a respective implantation region 240 are arranged substantially in a common first plane parallel to the surface 260 of the diamond 220 after carrying out the method 100, wherein the NV centers of the second lattice are arranged substantially in a common second plane parallel to the surface 260 of the diamond 220 after carrying out the method 100, and wherein the first plane has a first distance from the surface 260 of the diamond 220, and wherein the second plane has a second distance from the surface 260 of the diamond 220, and wherein the first distance is different from the second distance. This enables the production of more complex lattices and more complex lattice unit cells.By arranging the NV centers and / or the NV center pairs of the first and second lattices in spaced-apart planes parallel to the diamond surface 260, a targeted three-dimensional structuring of the diamond lattice is achieved. The difference in the distances to the surface 260 allows the defined formation of complex lattice unit cells in the vertical direction, thus supporting the realization of multilayer quantum registers with specifically controllable coupling properties.

[0068] In an eighteenth variant of the method 100, the smallest distance between a first NV center of the first grating and a directly adjacent second NV center of the second grating deviates by no more than 20% and / or no more than 10% and / or no more than 5% and / or no more than 3%, preferably no more than 10%, from the smallest distance 250 between the first NV center of the first grating and the third NV center of the first grating that is most closely adjacent to the first NV center of the first grating. This has the advantage that the coupling strengths of the NV centers are very similar to one another. By deliberately limiting the deviation in the distance between NV centers of different gratings to preferably no more than 10% of the smallest intra-grating distance, a homogeneous spatial distribution is achieved. This leads to comparable coupling strengths between the NV centers.NV center pairs and enables precise tuning of the quantum mechanical interactions, which is particularly advantageous for scalable and symmetric quantum registers.

[0069] The document presented here further discloses a set of n quantum registers in a diamond in a viewing area on the surface 260 of the diamond 220. The quantum registers then typically correspond to the implantation regions 240. Here, n should be a positive integer greater than 0. The quantum registers (implantation regions 240) are preferably located directly beneath the surface 260 of the diamond 220. Each quantum register (implantation region 240) comprises up to o single-ion implanted nitrogen atoms and / or up to p single-molecule implanted nitrogen-containing molecules and / or up to q single-molecule implanted N2 molecules. Where o can be a positive integer including 0 and less than or equal to n. Where p can be a positive integer including 0 and less than or equal to n. Here, p should be a positive integer including 0 and less than or equal to n, and m should be a positive integer greater than or equal to 1.Here, in particular, the total number of implanted nitrogen-containing objects should be m (o+p+q=m). The distances of the implantation positions 230 between two adjacent implantation positions 230 of two adjacent implanted, in particular single-ion implanted and / or single-molecule implanted, nitrogen atoms within a respective quantum register (implantation region 240) of the n quantum registers (implantation regions 240) are preferably each less than 40 nm and / or less than 30 nm and / or less than 20 nm and / or less than 10 nm, preferably less than 20 nm. Of the n quantum registers (implantation regions 240) in the diamond 220, more than m*(0.9*0.8) form the quantum registers (implantation regions 240). mQuantum registers (implantation regions 240) of the n quantum registers (implantation regions 240) form a quantum register with m quantum bits in the form of NV centers. Each of the NV centers of a quantum register with m quantum bits in the form of the NV centers of these quantum registers can be coupled and / or entangled with at least one neighboring quantum bit of this quantum register, in particular by means of ODMR methods and in particular using pump radiation pulses with a pump radiation wavelength of 490 nm to 540 nm—preferably 532 nm—and microwave pulses. The device allows the parallel realization of a plurality of n closely spaced quantum registers, each with m quantum bits, preferably comprising paramagnetic centers such as NV centers, in a common observation region of a diamond.The precise arrangement of the nitrogen implants with spacings of less than 20 nm enables efficient coupling (dipole-dipole coupling) and entanglement of the NV centers within a register. This allows for the scalable fabrication of structured quantum registers for applications in quantum information processing.

[0070] In a first variant, the distance 270 of each NV center of a first quantum register (first implantation region 240) of the n quantum registers (implantation regions 240) to each NV center of a second quantum register (second implantation region 240) of the n quantum registers (implantation regions 240), which is different from the first quantum register (first implantation region 240), is preferably greater than 100 nm and / or greater than 200 nm and / or greater than 500 nm and / or greater than 1 pm, wherein in particular a distance 270 greater than twice the pump radiation wavelength is preferred. By deliberately choosing a minimum distance of preferably more than twice the pump radiation wavelength between NV centers of different quantum registers, unwanted optical or microwave-based interactions between neighboring quantum registers or NV center groups are effectively suppressed.This variant improves the addressability and isolation of individual registers and thus enables the trouble-free parallel operation of several quantum registers or NV center groups in a small space.

[0071] In a second variant, n is greater than 2 and / or greater than 5 and / or greater than 10 and / or greater than 1 / (0, 9*0, 8) m . By forming more than 2, 5 or 10 quantum registers, in particular more than 1 / (0.9 x 0.8) m Quantum registers, despite unavoidable losses during NV center formation, provide a sufficient number of fully functional quantum registers. This variant of method 100 significantly increases the yield of m-qubit quantum registers, thus enabling the reliable realization of complex quantum-based computing or sensor systems on a single diamond substrate.

[0072] In a third variant, in a quantum register of the n quantum registers, an NV center is not formed at all m implantation positions of the quantum register of the n quantum registers in the observation region of the diamond. In this third variant, in a quantum register of the n quantum registers, an NV center defect 280 is formed as a lattice defect of the NV center lattice of a quantum register of the n quantum registers in the observation region of the diamond at some of the m implantation positions of the quantum register of the n quantum registers. By designing that an NV center is not formed at all m implantation positions in a quantum register, the fact that NV center formation is subject to statistical fluctuations despite optimized process control is taken into account.This variant still allows the use of such partially occupied registers, thereby increasing the overall yield of functionally usable quantum registers in the area of ​​consideration and enabling more flexible applications.

[0073] The result of the method 100 is a diamond substrate 220 with properties that originate from the method 100 described above. The technical teaching presented here proposes a quantum computer based on NV centers that uses this diamond substrate 220 as a diamond chip. Preferably, the quantum computer comprises a set of n quantum registers 240 with NV centers in a diamond 220, as can be produced, for example, in the method 100 described above. Preferably, the quantum computer comprises means for selecting one or more implantation regions 240 as active quantum registers 240, which the quantum computer uses to perform quantum operations. Such means can, for example, be positioning devices that can move the diamond chip 220 with the implantation regions 240 relative to an optical system of the quantum computer. As an example of such a quantum computer, the technical teaching of

[0074] WO 2023 170054 A1, in which such positioning devices are described.

[0075] List of characters

[0076] Figure 1 shows the sequence of the proposed procedure.

[0077] Figure 2 shows the sequence of the proposed procedure with a repositioning of the implantation site before the subsequent implantation.

[0078] Figure 3 shows the sequence of the proposed method with detection of single ions or single molecules during implantation.

[0079] Figure 4 shows the arrangement of the implantation positions with a square grid.

[0080] Figure 5 shows the arrangement of the implantation positions with a hexagonal grid.

[0081] Figure 6 shows the arrangement of the implantation positions with a hexagonal lattice with NV center lattice defects.

[0082] Figure 7 shows an exemplary hexagonal grid of implantation regions (240) in which respective grids of implantation positions (230) are located, wherein the grid structures are examples of possible grid structures such as hexagonal, square, one-dimensional.

[0083] List of cited writings

[0084] If, in the context of the nationalization of a subsequent international application, the law of the respective legal system of the state in which the international application of the document presented here is nationalized permits disclosure by reference, the content of the following documents forms an integral part of the disclosure presented here.

[0085] Saada, D., Joan Adler, and R. Kalish. "Sulfur: A potential donor in diamond." Applied Physics Letters 77.6 (2000): 878-879.

[0086] E. Gheeraert, N. Casanova, A. Tajani, A. Deneuville, E. Bustarret, J.A. Garrido, C.E. Nebel, M. Stutzmann, n-Type doping of diamond by sulfur and phosphorus, Diamond and Related Materials, Volume 11, Issues 3-6, 2002, Pages 289-295, ISSN 0925-9635, https: / / doi.org / 10.1016 / S0925- 9635(01)00683-5.

[0087] Matsushita, H., Hirose, S., Yagita, T. et al. Detection of particles in the ion beam. MRS Advances 7, 1509-1514 (2022). https: / / doi.org / 10.1557 / s43580-022-00394-0 Räcke, P., J. Meijer, and D. Spemann. "Image charge detection of ion bunches using a segmented, cryogenic detector." Journal of Applied Physics 131.20 (2022).

[0088] Lühmann, Tobias, et al. "Coulomb-driven single defect engineering for scalable qubits and spin sensors in diamond." Nature communications 10.1 (2019): 4956

[0089] Dolde, Florian, et al. "Room-temperature entanglement between single defect spins in diamond." Nature Physics 9.3 (2013): 139-143,

[0090] Dolde, Florian, et al. "High-fidelity spin entanglement using optimal control." Nature communications 5.1 (2014): 3371

[0091] Shagieva, F., et al. "Microwave-assisted cross-polarization of nuclear spin ensembles from optically pumped nitrogen-vacancy centers in diamond." Nano letters 18.6 (2018): 3731-3737 DE 10 2024 115 169 Al, PCT / DE 2025 / 100 132, EP 3 990 684 CO, DE 10 2019 117 423 Al,

[0092] DE 10 2020 007 977 B4, DE 10 2020 008 243.2, DE 10 2015 106 769 Al, DE 10 2019 117 423 Al,

[0093] DE 10 2020 101 784 B4, DE 10 2019 120 716 Al, DE 10 2015 106 769 Al, DE 10 2015 106 769 Al,

[0094] WO 2023 170 054 Al

Claims

Patent claims 1. Method (100) for producing one or more NV centers (230) in diamond (220) comprising the steps Providing (110) a diamond (220) having a surface (260), wherein the diamond (220) may have a raised Fermi level upon provision (n-doped diamond (220)); Defining (120) an implantation area (240) on the surface (260) of the diamond (220); If (130) the Fermi level, in particular in the implantation region (240) of the diamond (220), is below -2.9 eV to -0.5 eV from the conduction band edge and / or below -1.2 eV to -0.5 eV and / or below -0.8 eV to -0.5 eV from the conduction band edge in the band gap of the diamond material of the diamond, N-doping (140) at least of the implantation region (240) of the diamond (220) to raise (140) the Fermi level at least in the implantation region (240) of the diamond (220) to a value between -2.9 eV to -0.5 eV from the conduction band edge in the band gap of the diamond material of the diamond (220), wherein a Fermi level of -0.5 eV from the conduction band edge in the band gap of the diamond material of the Diamond (220) is located at least in the implantation region (240) of the diamond (220) after the n-doping (140) is preferred; Determining (150) an implantation position (230) on the surface (260) of the diamond (220) within one of the implantation areas (240); Second implantation (160) of one or more nitrogen isotopes, in particular one or more 15 N or 14 N nitrogen isotopes, by means of focused single ion implantation and / or by means of focused molecule implantation with an implantation energy of 9.5 keV per implanted nitrogen ion (per nitrogen isotope) into the implantation region (240) of the diamond (220) at the implantation position (230) with a tolerance of + / - 5 keV and / or with a tolerance of + / - 2 keV and / or with a tolerance of + / - 1 keV and / or with a tolerance of + / - 0.5 keV and / or with a tolerance of + / - 0.2 keV and / or with a tolerance of + / - 0.1 keV and / or with a tolerance of + / - 0.05 keV and / or with a tolerance of + / - 0.02 keV and / or with a tolerance of + / - 0.01 keV, wherein 9.5 keV is used as implantation energy per nitrogen atom (per nitrogen isotope) is preferred and wherein the implantation energy of the nitrogen atoms (the nitrogen isotopes) is preferably above 4 keV per implanted nitrogen isotope; Second heat treatment (170) of the diamond at 800°C with a tolerance of + / - 80°C and / or with a tolerance of + / - 40°C and / or with a tolerance of + / - 20°C and / or with a tolerance of + / - 10°C and / or with a tolerance of + / - 5°C and / or with a tolerance of + / - 2°C and / or with a tolerance of + / - 1°C and / or with a tolerance of + / - 0.5°C and / or with a tolerance of + / - 0.2°C and / or with a tolerance of + / - 0.1°C and / or with a tolerance of + / - 0.05°C and / or with a tolerance of + / - 0.02°C and / or with a tolerance of + / - 0.01°C, with 800°C being preferred.

2. Method (100) according to claim 1, wherein the second implantation (160) of the nitrogen isotopes, in particular the 15 N or 14N nitrogen isotopes, by focused molecular implantation of nitrogen-containing molecules that contain the nitrogen isotopes, in particular the 15 N or 14 N nitrogen isotopes, with an implantation energy of 9.5keV per implanted nitrogen isotope with the above tolerances in the implantation region (240) of the diamond (220) at the implantation position (230).

3. Method (100) according to claim 2, wherein the second implantation (160) of the nitrogen isotopes, in particular the 15 N or 14 N nitrogen isotopes, ionized IXk molecules by focused molecule implantation, which contain the nitrogen isotopes, in particular the 15 N or 14 N nitrogen isotopes, with an implantation energy of 9.5keV per implanted nitrogen isotope (19keV implantation energy for the Na molecule) with the above tolerances in the implantation region (240) of the diamond (220) at the implantation position (230).

4. The method (100) according to any one of claims 1 to 3, wherein the raising (140) of the Fermi level is carried out by means of singly positively ionized sulfur atoms (S+), which have an energy level of -0.5 eV from the conduction band edge, as doping atoms (donors) in the diamond material of the diamond (220) in the implantation region (240).

5. Method (100) according to one of claims 1 to 4, wherein the raising (140) of the Fermi level is effected by first implanting (193) of Sulfur atoms by means of ion implantation with an implantation energy of 40 keV per implanted sulfur ion into the implantation region (240) of the diamond (220) with a tolerance of + / - 10 keV and / or with a tolerance of + / - 5 keV and / or with a tolerance of + / - 2 keV and / or with a tolerance of + / - 1 keV and / or with a tolerance of + / - 0.5 keV and / or with a tolerance of + / - 0.2 keV and / or with a tolerance of + / - 0.1 keV and / or with a tolerance of + / - 0.05 keV and / or with a tolerance of + / - 0.02 keV and / or with a tolerance of + / - 0.01 keV, wherein 40 keV is preferred as the implantation energy of the sulfur atoms and wherein the method (100) comprises the step of a first implantation (193) of sulfur atoms following this first implantation Heat treatment (195) of the diamond (220) at more than 800°C and / or more than 900°C and / or more than 1000°C and / or more than 1100°C and / or more than 1200°C and / or more than 1300°C.

6. The method (100) of claim 5, wherein the first implantation (193) of the sulfur is carried out at a dose of 10 17 cm -2 + / -20% and / or + / -10% and / or + / -5% and / or + / -2% and / or + / -1%, whereby a dose of 10 17 cm -2 is preferred.

7. Method (100) according to one of claims 1 to 6, wherein the method (100) comprises the repeated execution of a method (100) according to one of claims 1 to 3 at different implantation positions (230) for each implanted nitrogen atom or implanted nitrogen-containing molecule or implanted N2 molecule, and wherein the NV center formation rate of the implanted nitrogen atoms is calculated down or calculated up to 100 virtual implanted nitrogen atoms from the virtual 100 implanted nitrogen atoms 80 virtual implanted nitrogen atoms (80% yield) and / or 81 to 79 virtual implanted nitrogen atoms (79% to 81% yield) and / or 83 to 77 virtual implanted nitrogen atoms (77% to 83% yield) and / or 86 to 74 virtual implanted nitrogen atoms (74% to 86% yield) and / or 92 to 68 virtual implanted nitrogen atoms (69% to 92% yield) and / or 100 to 60 virtual implanted nitrogen atoms (60% to 100% yield) form an NV center within the diamond, with a yield >80% being preferred.

8. The method (100) according to any one of claims 1 to 7, wherein the method (100) comprises carrying out a method (100) according to any one of claims 1 to 3 several times at different implantation positions (230) for each implanted nitrogen atom or implanted nitrogen-containing molecule or implanted IXh molecule, and wherein the NV centers non-formation rate of the implanted nitrogen atoms is calculated down orextrapolated to 100 virtual implanted nitrogen atoms of the 100 virtual implanted nitrogen atoms, 20 virtual implanted nitrogen atoms (20% loss rate) and / or 19 to 21 virtual implanted nitrogen atoms (19% to 21% loss rate) and / or 17 to 23 virtual implanted nitrogen atoms (17% to 23% loss rate) and / or 14 to 26 virtual implanted nitrogen atoms (14% to 26% loss rate) and / or 8 to 32 virtual implanted nitrogen atoms (8% to 32% loss rate) and / or 0 to 40 virtual implanted nitrogen atoms (0% to 40% loss rate) do not form an NV center within the diamond.

9. The method (100) according to any one of claims 1 to 8, wherein the second implantation (160) of the nitrogen atoms is carried out by means of a single ion implanter or by means of a single molecule implanter with a detection probability for the second implantation >90% and / or >95% and / or >98% and / or >99% and / or >99.5% and / or >99.7% and / or >99.8% and / or / 99.9%, wherein a detection probability >99.9% is preferred.

10. Method (100) according to one of claims 1 to 9 and according to one of claims 1 to 3, wherein the method (100) according to one of claims 1 to 3 is carried out at at least two different implantation positions (230) in the same implantation area (240), at least a first implantation position (230) and a second implantation position (230) in the implantation area (240), and wherein the first implantation position (230) is different from the second implantation position (230) and wherein the distances (250) of the implantation positions (230) between two adjacent implantation positions (230) of two adjacent single-ion implanted and / or single-molecule implanted nitrogen atoms are less than 40 nm and / or less than 30 nm and / or less than 20 nm and / or less than 10 nm, preferably 20 nm.

11. Method (100) according to one of claims 1 to 10 and according to one of claims 1 to 3, wherein the method (100) according to one of claims 1 to 3 is carried out at at least three different implantation positions (230) in the same implantation region (240), at least a first implantation position (230) and a second implantation position (230) and a third implantation position (230) in the implantation region (240), and wherein the implantation positions (230) are different from one another and wherein the implantation positions (230) are arranged in a one- or two-dimensional grid with respect to a projection perpendicular to the surface (260) of the diamond (220) onto the plane of the two-dimensional surface (260) of the diamond (220), and wherein the real implantation positions (230) differ by less than 5 nm and / or less than 3 nm and / or less than 2 nm and / or less than lnm, preferably less than 3nm, from the ideal lattice position.

12. The method (100) according to any one of claims 1 to 11, wherein the real positions of the successfully generated NV centers are arranged in a one-dimensional or two-dimensional grid relative to a projection perpendicular to the surface (260) of the diamond (220) onto the plane of the two-dimensional surface (260) of the diamond (220), and wherein these real positions of the NV centers deviate from the ideal grid position by less than 10nm and / or less than 5nm and / or less than 2nm and / or less than 1nm.

13. The method (100) according to any one of claims 11 to 12, wherein the grid of said real position and / or of the implantation positions (230) is a two-dimensional hexagonal grid or a two-dimensional square grid. or a two-dimensional rectangular lattice or a one-dimensional lattice.

14. The method (100) according to any one of claims 11 to 13, wherein the method (100) comprises fabricating a first grid of NV centers at first implantation positions (230) in the implantation region (240) of the diamond (220), and wherein the method (100) comprises fabricating a second grid of NV centers at second implantation positions (230) in the implantation region (240) of the diamond (220), and wherein the first implantation positions (230) are different from the second implantation positions (230).

15. Method (100) according to one of claims 11 to 14, wherein the method (100) in the context of the second implantation (160) of one or more first nitrogen isotopes, in particular one or more first 15 N or 14N nitrogen isotopes, by means of a first focused single ion implantation and / or by means of a first focused molecule implantation with a first implantation energy of 9.5 keV per implanted nitrogen ion (per nitrogen isotope) into the implantation region (240) of the diamond (220) with a first implantation energy, a first grid of first NV centers in the implantation region (240) of the diamond (220) at first implantation positions (230) in the implantation region (240) with a tolerance of + / - 5 keV and / or with a tolerance of + / - 2 keV and / or with a tolerance of + / - 1 keV and / or with a tolerance of + / - 0.5 keV and / or with a tolerance of + / - 0.2 keV and / or with a tolerance of + / - 0.1 keV and / or with a tolerance of + / - 0.05 keV and / or with a tolerance of + / - 0.02keV and / or with a tolerance of + / - 0.01keV, with a first implantation energy of 9.5 keV per implanted first nitrogen isotope is preferred and wherein and wherein preferably the first implantation energy of the first nitrogen atoms is above 4 keV per implanted nitrogen isotope; wherein the method (100) in the context of the second implantation (160) of one or more second nitrogen isotopes, in particular one or more second, 15 N or 14 N nitrogen isotopes, by second focused single ion implantation and / or second first focused molecule implantation with a second implantation energy into the implantation region (240) of the diamond (220) with a second implantation energy creates a second lattice of second NV centers in the implantation region (240) of the diamond (220) at second implantation positions (230) in the implantation region (240), wherein preferably the second implantation energy of the first nitrogen atoms is above 4 keV per implanted nitrogen isotope; wherein the first implantation positions (230) are different from the second implantation positions (240).

16. The method (100) of claim 15, wherein the first grid is a hexagonal grid and wherein the second grid is a hexagonal grid.

17. The method (100) of claim 15 or 16, wherein the first implantation energy is different from the second implantation energy.

18. The method (100) according to any one of claims 11 to 17, wherein the NV centers of the first lattice are arranged substantially in a common first plane parallel to the surface of the diamond after performing the method (100), and wherein the NV centers of the second lattice are arranged substantially in a common second plane parallel to the surface of the diamond after performing the method (100), and wherein the first plane is at a first distance from the surface of the diamond, and wherein the second plane is at a second distance from the surface of the diamond, and wherein the first distance is different from the second distance.

19. Method (100) according to one of claims 11 to 18, wherein the smallest distance of a first NV center of the first grid to a directly adjacent second NV center of the second grid is not more than 20% and / or not more than 10% and / or not more than 5% and / or not more than 3%, preferably not more than 10%, of the smallest distance of the first NV- Center of the first grid to the third NV center of the first grid that is closest to the first NV center of the first grid.

20. A set of n quantum registers (240) in a diamond (220) in a Viewing area on the surface (260) of the diamond (220), wherein the quantum registers are located directly beneath the surface (260) of the diamond (220), and wherein each quantum register comprises up to 0 single-ion implanted nitrogen atoms and / or up to p single-molecule implanted nitrogen-containing molecules and / or up to q single-molecule implanted N2 molecules, wherein in particular the number of implanted nitrogen-containing objects is m in total (o+p+q=m), and wherein the distances of the implantation positions (230) between two respectively adjacent implantation positions (230) of two respective adjacent implanted, in particular single-ion implanted, nitrogen atoms within a respective quantum register (240) of the n quantum registers (240) are each less than 40 nm and / or less than 30 nm and / or less than 20 nm and / or less than 10 nm, preferably less than 20nm,and where of the n quantum registers (240) in the diamond (220) more than m*(0.9*0.8), m Quantum registers (240) of the n quantum registers (240) form a quantum register (240) with m quantum bits in the form of NV centers, and wherein each of the NV centers of a quantum register (240) with m quantum bits in the form of NV centers of these quantum registers (240) can be coupled and / or entangled with at least one adjacent quantum bit of this quantum register (240), in particular by means of ODMR methods and in particular using pump radiation pulses with 490 nm to 540 nm - preferably 532 nm - pump radiation wavelength and microwave pulses.

21. A set of n quantum registers (240) in the diamond (220) according to claim 20, wherein the distance of each NV center of a first quantum register (240) of the n Quantum register (240) to each NV center of a second quantum register (240) of the n quantum registers (240) which is different from the first quantum register (240), greater than 100nm and / or greater than 200nm and / or greater than 500nm and / or greater than 1pm, with a distance greater than twice the pump radiation wavelength being particularly preferred.

22. A set of n quantum registers (240) in the diamond (220) according to claim 20 or 21, wherein n is greater than 2 and / or greater than 5 and / or greater than 10 and / or greater than 1 / (0.9*0.8) m23. A set of n quantum registers (240) in the diamond (220) according to claim 22, wherein, in a quantum register (240) of the n quantum registers (240), not all m implantation positions (230) of the quantum register (240) of the n quantum registers (240) have an NV center formed in a quantum register (240) of the n quantum registers (240) in the field of view of the diamond (220).

24. A quantum computer based on NV centers, wherein the quantum computer comprises a set of n quantum registers (240) with NV centers in a diamond (220) according to any one of claims 20 to 23.

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