Diamond beryllium-vacancy quantum color center, applications and preparation methods

Abstract

The present application discloses a diamond beryllium-vacancy quantum color center, its applications and preparation methods. In this technical solution, a diamond beryllium-vacancy quantum color center is designed. This quantum color center can maintain the ground state triplet state at room temperature, and its zero phonon line is within 575 nm. In the visible light range, it is easy to perform fluorescence recognition; this quantum color center can maintain a relatively stable charge state. Based on quantum control technology, this beryllium-vacancy quantum color center can be applied to fields such as quantum sensing, quantum communication, and quantum computing.

Description

Technical Field

[0001] This application relates to the technical field of quantum information technology, and particularly to diamond beryllium-vacancy quantum color centers, applications, and preparation methods. Background Art

[0002] Diamond is a wide-bandgap material with extremely high hardness, high thermal conductivity, and high chemical stability. Therefore, diamond materials containing quantum color centers can be applied in complex and harsh environments.

[0003] Diamond quantum color centers, represented by nitrogen-vacancy color centers, are quantum spin systems with a ground-state triplet. Diamond nitrogen-vacancy color centers have a coherence time of milliseconds at room temperature, are easily coherently controlled by lasers, and can be applied in quantum information fields such as quantum sensing, quantum computing, and quantum communication. Diamond quantum color centers have an atomic-scale size, so they can be applied in the field of microscopic quantum information, such as in quantum sensing technology at the micro-nano scale, and can be applied in biological, chemical, and physical research.

[0004] Diamond nitrogen-vacancy color centers still contain many defects that affect their coherence properties, their coherence time needs to be further improved, and their fluorescence intensity is also weak. Nitrogen-vacancy color centers also have the disadvantage of charge instability, which means that nitrogen-vacancy color centers will produce fluorescence blinking and cannot be further stably quantum-controlled. Researchers have been looking for other color centers to enrich the research of diamond quantum color centers. Other common diamond quantum color centers are silicon-vacancy color centers, phosphorus-vacancy color centers, and germanium-vacancy color centers, etc. The design criteria for diamond quantum color centers are based on the criteria proposed by Professor DAVID AWSCHALOM of the University of California [Weber J R, Koehl W F, Varley J B, et al. Quantum computing with defects. Proceedings of the National Academy of Sciences, 2010, 107(19): 8513-8518], mainly including: the laser wavelength from the ground state to the excited state must be within a reasonable range (able to find a suitable laser), and the color center defect state must be able to resist temperature fluctuations (i.e., ensure the ground-state triplet at room temperature), etc.

[0005] The main methods for preparing diamond quantum color centers are chemical vapor deposition (CVD) method and ion implantation method. The diamond material prepared by the CVD method has fewer defects and less quantum noise; for the quantum color centers prepared by the ion implantation method, the advantage is that the position controllability of the color centers is relatively high, and the disadvantage is that there are more defects and the crystal quality is poor. However, for relatively active metal elements and toxic elements, it is not suitable to use the CVD method to dope them into the diamond, because relatively active metal elements are difficult to prepare, and toxic elements are likely to remain in the growth chamber, which may eventually contaminate the chamber and affect the growth of the diamond film. Therefore, when it comes to relatively active metal elements and toxic elements, it is more appropriate to use the ion implantation method. Summary of the Invention

[0006] In view of this, the present application provides a diamond beryllium-vacancy quantum color center, its applications and preparation methods, which can be widely applied in the field of quantum information.

[0007] In the first aspect, the present application provides a diamond beryllium-vacancy quantum color center, which is a diamond quantum color center structure formed with Be atoms as the color center vacancies.

[0008] Suitably but not restrictively, in the diamond quantum color center structure, it also includes N and / or P atoms as doping defect atoms.

[0009] In the second aspect, the present application provides an application of the diamond beryllium-vacancy quantum color center as described above, and its application in visible light fluorescence recognition.

[0010] Suitably but not restrictively, the wavelength of the visible light is around 575 nm.

[0011] In the third aspect, the present application provides an application of the diamond beryllium-vacancy quantum color center as described above, and its application in quantum materials.

[0012] In the fourth aspect, the present application provides a preparation method of the diamond beryllium-vacancy quantum color center as described above, including the following steps:

[0013] S1. Provide diamond;

[0014] S2. Incorporate beryllium atoms into the diamond by ion implantation method;

[0015] S3. Perform post-treatment including annealing on the diamond treated in S2;

[0016] S4. Make the diamond after post-treatment form a diamond quantum color center structure.

[0017] Suitably but not restrictively, in S1, the diamond is single crystal diamond.

[0018] Suitably but not restrictively, before S1, surface treatment of the diamond is also included.

[0019] Suitably but not restrictively, the post-treatment also includes surface treatment after annealing.

[0020] The above provides a beryllium-vacancy quantum color center in diamond, its applications and preparation methods, and designs a beryllium-vacancy quantum color center in diamond. This quantum color center can maintain the ground state triplet at room temperature, and the zero phonon line is within 575 nm.

[0021] Within the visible light range, it is easy to perform fluorescence recognition; this quantum color center can maintain a relatively stable charge state. Further, based on quantum control technology, this beryllium-vacancy quantum color center can be applied to fields such as quantum sensing, quantum communication, and quantum computing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following, in conjunction with the drawings, through a detailed description of the specific embodiments of the present application, will make the technical solutions and other beneficial effects of the present application obvious.

[0023] 0 Figure 1 This is the microscopic structure diagram of the beryllium-vacancy quantum color center provided by the embodiment of the present application.

[0024] Figure 2 This is the energy level diagram of the beryllium-vacancy quantum color center provided by the embodiment of the present application.

[0025] Figure 3 This is the ground state spin electron density diagram of the beryllium-vacancy quantum color center provided by the embodiment of the present application.

[0026] Figure 4 This is the formation energy diagram of the beryllium-vacancy structure in different charge states provided by the embodiment of the present application.

[0027] Figure 5 This is the flow chart of the preparation method of the beryllium-vacancy quantum color center provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will, in conjunction with the embodiments of the present application, clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present application.

[0029] 0 In the description of the present application, it should be understood that the terms "first" and "second" are only used for descriptive purposes.

[0030] It should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second" may explicitly or implicitly include one or more of the said features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0031] 5 In the description of this application, it should be noted that unless otherwise clearly stipulated and defined, the terms "install", "connect", "link" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection or a connection capable of mutual communication; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal connection of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032]

[0033] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure of this application, components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit this application. In addition, this application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0034] As Figure 1 shown, it is the microscopic structure of beryllium-vacancy quantum color center Figure 1 .

[0035] As Figure 1 shown, the largest "sphere" in the middle is the beryllium element, and the other "spheres" are carbon elements.

[0036] As Figure 1 shown, beryllium-vacancy means that in diamond, a beryllium atom replaces a carbon atom A, and a carbon atom B adjacent to the beryllium atom is removed to become a "vacancy". After relaxation, the beryllium atom moves between carbon atom A and the "vacancy", that is, a beryllium-vacancy structure is formed.

[0037] As Figure 2 shown, it is the energy level diagram of beryllium-vacancy quantum color center, which is obtained by first-principles calculation using the HSE06 hybrid functional. This energy level diagram refers to the valence electron energy level position in the ground state of beryllium-vacancy quantum color center.

[0038] As Figure 2 shown, the valence electron energy levels of the beryllium-vacancy quantum color center are a 1 (1), a 2 (2), e x , e y , a 1 (1)’, a 2 (2)’, e x ’, e y ’. Among them, a 1 (1), a 2 (2), e x , e y are the occupied states of the up spin, a 1 (1)’, a 2 (2)’ are the occupied states of the down spin, and e x ’, e y ’ are the unoccupied states of the down spin.

[0039] As Figure 2 shown, the ground state of the beryllium-vacancy quantum color center is a triplet state, and the electrons in the triplet state come from e x , e y , which meets the basic conditions of the quantum color center.

[0040] As Figure 2 shown, the energy level difference between e x and e x ’ of the beryllium-vacancy quantum color center is about 2.46 eV, and the energy level difference between e y and e y ’ is about 2.46 eV. 2.46 eV is large enough for the quantum color center to exist stably at room temperature. That is, at room temperature, the electrons on e x or e y will not spontaneously transition to e x ’ or e y ’, and the ground state spin triplet state can be maintained.

[0041] As Figure 3 shown, when it is the ground state of the beryllium-vacancy quantum color center, it is the electron density map corresponding to the addition of e x and e y . This map is obtained by first-principles calculation, using the HSE06 hybrid functional. The electron cloud is mainly concentrated near the beryllium-vacancy quantum color center, and this electron cloud is also the main electron source of the ground state spin triplet state.

[0042] As Figure 4 shown, it is the formation energy diagram of the beryllium-vacancy (Be-Vacancy, abbreviated as BeV) structure in different charge states. BeV 0 , BeV 1 , BeV -1, BeV -2 , BeV 2 represent the 0, 1, -1, -2, and 2 charge states of BeV, respectively. This figure is obtained through first-principles calculations using the HSE06 hybrid functional. The formation energy is based on the formation energy of BeV 0 , that is, it is assumed that the formation energy of BeV 0 is 0 eV. The beryllium-vacancy quantum color center specifically refers to BeV -2 , that is, the case when BeV is in the -2 valence state.

[0043] To make the charge state of the beryllium-vacancy quantum color center more stable, it is necessary to increase the Fermi level of diamond, mainly by implanting phosphorus atoms to increase the Fermi level of diamond materials.

[0044] According to first-principles calculations, the zero-phonon line of the beryllium-vacancy quantum color center is around 575 nm, which is within the visible light wavelength range observable by the human eye.

[0045] When the beryllium-vacancy quantum color center is in the ground-state triplet state, when light irradiates the beryllium-vacancy quantum color center, an electron on a 1 (1)' or a 2 (2)' will be excited to the e x ' or e y ' orbit, making the excited state also a triplet state. When the beryllium-vacancy quantum color center is in the excited-state triplet state, when an electron on the e x ' or e y ' orbit falls back to a 1 (1)' or a 2 (2)', then fluorescence will be observed from the beryllium-vacancy quantum color center. The zero-phonon line of the beryllium-vacancy color center is measured to be around 575 nm through Raman spectroscopy.

[0046] As Figure 5 shown, it is the steps for preparing the diamond beryllium-vacancy quantum color center.

[0047] Step 1: Prepare a single-crystal diamond sample and perform surface pretreatment. The size of the diamond sample is 3 mm * 3 mm * 0.25 mm, but it is not limited to this.

[0048] Step 2: Inject beryllium atoms through an ion implanter. Beryllium is a toxic element and is suitable for doping into diamond by ion implantation.

[0049] Step 3: Inject phosphorus atoms again through an ion implanter to increase the Fermi level of diamond.

[0050] Step 4: Perform post-treatment operations such as annealing and surface treatment on the diamond. Annealing is mainly to gradually migrate the atomic vacancies in the diamond to the vicinity of beryllium atoms to form a beryllium-vacancy structure.

[0051] Step 5: Obtain a diamond containing beryllium-vacancy color centers. The zero phonon line of gallium-vacancy color centers is measured to be around 575 nm by Raman spectroscopy. This diamond containing beryllium-vacancy color centers can be used in fields such as quantum sensing, quantum communication, and quantum computing.

[0052] As described above, it is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application.

Claims

1. A diamond beryllium-vacancy quantum color center, characterized in that, The diamond quantum color center structure formed with Be atoms as color center vacancies, and the beryllium-vacancy quantum color center specifically refers to BeV -2 , that is, BeV is in a -2 valence state; in the diamond quantum color center structure, it also includes N and / or P atoms as doped defect atoms; this quantum color center can maintain the ground state triplet at room temperature, and the zero phonon line is around 575 nm.

2. An application of the diamond beryllium-vacancy quantum color center according to claim 1, characterized in that, its application in visible light fluorescence recognition.

3. According to the application described in claim 2, characterized in that, the wavelength of the visible light is around 575 nm.

4. An application of the diamond beryllium-vacancy quantum color center according to claim 1, characterized in that, its application in quantum materials.

5. A preparation method of the diamond beryllium-vacancy quantum color center according to claim 1, characterized in that, comprising the following steps: S1. Provide diamond; S2. Incorporate beryllium atoms into the diamond by ion implantation method; S3. Perform post-treatment including annealing on the diamond treated in S2; S4. Make the diamond after post-treatment form a diamond quantum color center structure.

6. According to the preparation method described in claim 5, characterized in that, in step S1, the diamond is single crystal diamond.

7. According to the preparation method described in claim 5, characterized in that, before S1, surface treatment of the diamond is also included.

8. According to the preparation method described in claim 5, characterized in that, the post-treatment also includes surface treatment after annealing.

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