Quantum chip and application thereof

Abstract

The application discloses a quantum chip and application thereof, and the chip comprises a sensing element substrate, an optical channel substrate and a sealing plate; the sensing element substrate is integrated with a microwave antenna, a first light source, a second light source, a diamond NV color center and two guide mirrors; the optical channel substrate is integrated with a first reflector and a second reflector, and an optical resonance loop is formed by the first reflector, the second reflector and a reflector surface of the diamond NV color center; and the sealing plate is integrated with a first photodetector, a second photodetector and a third photodetector, and the three photodetectors are respectively used for detecting fluorescence, absorbed light and excitation light. The chip can be used as a sensing element in a quantum current transformer. The application can improve light intensity through the resonance loop, has the advantages of simple structure, easy integration and miniaturization, can realize switching of two kinds of measurement principles, has the advantages of simple structure and simple production process, and can realize size miniaturization.

Description

Technical Field

[0001] This invention relates to the field of quantum sensing chips, specifically a quantum chip and its applications. Background Technology

[0002] Currently, the principle of traditional magnetic sensors based on diamond NV centers is a precise cyclic process based on optical detection of magnetic resonance. It begins with optical initialization: using a green laser to efficiently polarize and prepare the electron spins of the diamond NV centers into the ground state energy level. In this state, the fluorescence intensity is strongest. When the magnetic field to be measured is present, according to the Zeeman effect, the diamond NV color center will undergo energy level transitions due to the external magnetic field to be measured (i.e., Next comes magnetic resonance manipulation: a frequency-scanning microwave field is applied to the diamond NV color center, and the microwave frequency is adjusted to match the energy level transition frequency that shifts due to the external magnetic field (i.e., At precise resonance, the spin population is altered. Then comes the spin state readout: due to being in... The color center of the spin state, under laser excitation, undergoes a significant decrease in fluorescence intensity via intersystem crossing pathways. Therefore, this spin state change is converted into a measurable attenuation of the fluorescence signal. Finally, in the data processing stage, by scanning the microwave frequency and recording the corresponding fluorescence intensity, an ODMR line with a characteristic "depression" is obtained. The shift Δν of the resonance frequency corresponding to this depression relative to the zero-field splitting value (2.87 GHz) is proportional to the magnetic field component B∥ along the NV axis. By accurately measuring Δν, nanoscale, highly sensitive quantitative detection of the magnetic field under test can be achieved.

[0003] Besides the magnetic field measurement technique of exciting the fluorescence of diamond NV centers with green lasers, existing technologies also utilize magnetic fields that are in the presence of... The NV center in the ground state exhibits selective absorption of 1042 nm infrared probe light. Magnetic field measurement systems, such as those described in patent CN116299098A, utilize this technology for magnetic field measurement. The specific principle of diamond NV center magnetometry based on selective infrared absorption is as follows: 532 nm pump light is used to spin-polarize the electrons in the NV center to the ground state. Energy levels, followed by the application of a swept microwave field; when the microwave frequency shifts relative to the Zeeman effect... At the resonance of the energy level transition frequency, the spin population changes, resulting in the state of... The NV color center in the state selectively absorbs 1042 nm infrared probe light; by monitoring the resonant attenuation of the infrared transmitted light intensity and calculating the corresponding microwave frequency shift, the external magnetic field can be quantitatively detected based on the microwave frequency shift. This prior art patent, with publication number CN116299098A, differs from traditional technologies that detect the weak fluorescence generated by the stimulated NV color center; it primarily detects changes in the intensity of infrared transmitted light.

[0004] Existing technologies for magnetic field measurement using green laser-excited diamond NV centers for fluorescence suffer from several drawbacks. Firstly, the fluorescence intensity emitted by the NV centers is low and its variation with the magnetic field is minimal, leading to measurement difficulties. Secondly, existing technologies, such as the magnetic measurement system constructed using the selective absorption of infrared probe light by NV centers as described in patent CN116299098A, suffer from poor intrinsic signal contrast (at room temperature, the absorption contrast of NV centers for 1042 nm infrared light (~1%) is far lower than the contrast of fluorescence detection methods (~30%)), resulting in high measurement difficulty and power consumption.

[0005] Therefore, existing technologies, whether based on green laser-induced fluorescence of diamond NV centers or on selective absorption of infrared probe light by NV centers, all suffer from the problem of high measurement difficulty. Summary of the Invention

[0006] This invention provides a quantum chip and its application to solve the problem of high measurement difficulty in existing magnetic field measurement techniques based on diamond NV centers.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A quantum chip, comprising: The sensing element substrate (2) integrates a microwave antenna (23), a first light source (24), a second light source (26), and a diamond NV color center (22). The diamond NV color center (22) is attached to the microwave antenna (23). One side of the diamond NV color center (22) faces away from the area between the first light source (24) and the second light source (26), while the other side faces the area between the first light source (24) and the second light source (26). The side of the diamond NV color center (22) facing away from the area between the first light source (24) and the second light source (26) is set as a reflective mirror. The first light source (24) is used to output excitation light, and the second light source (26) is used to output absorption light. The optical channel substrate (3) integrates a first reflector (36) and a second reflector (35), which are tilted relative to each other. One side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), so that the first reflector (36), the second reflector (35), and the diamond NV color center form a triangular distribution. The first reflector (36) is located on the output optical path of the first light source (24), and the second reflector (35) is located on the output optical path of the second light source (26). The reflective surfaces of the first reflector (36), the second reflector (35), and the diamond NV color center (22) form an optical resonant loop. The excitation light and the absorption light can be trapped and circulated multiple times in the optical resonant loop. During the circulation, the excitation light and the absorption light pass through the diamond NV color center (22). The excitation light is output through the first reflector (36), and the absorption light is output through the second reflector (35). The sealing plate (4) integrates a first photodetector (42), a second photodetector (43), and a third photodetector (44). One side of the sealing plate (4) is connected to the other side of the light channel substrate (3). The first photodetector (42) is used to detect the fluorescence generated by the diamond NV color center (22) when it is excited. The second photodetector (43) is used to detect the absorbed light output through the second reflector (35). The third photodetector (44) is used to detect the excitation light output through the first reflector (36).

[0008] Furthermore, the excitation light output by the first light source (24) is green light.

[0009] Furthermore, the absorbed light output by the second light source (26) is infrared light.

[0010] Furthermore, the sensing element substrate (2) also integrates two heat sinks, with the first light source (24) and the second light source (25) respectively disposed on the two heat sinks.

[0011] Furthermore, the optical channel substrate (3) is provided with an actuator corresponding to at least one reflector position, and the position of the corresponding reflector is adjusted by the actuator.

[0012] Furthermore, the optical channel substrate (3) also integrates a temperature control element (37). When one side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), the temperature control element (37) is located in the triangular region formed by the diamond NV color center (22), the first reflector (36), and the second reflector (35).

[0013] Furthermore, the sensing element substrate (2) is bonded to the optical channel substrate (3), and the optical channel substrate (3) is bonded to the cover plate (4).

[0014] Furthermore, the sensing element substrate (2) also integrates two guide mirrors (27). When one side of the sensing element substrate (2) is connected to the other side of the optical channel substrate (3), the two guide mirrors (27) are located on the transmission light paths of the first reflector (36) and the second reflector (35), respectively. One of the guide mirrors (27) guides the excitation light output through the first reflector (36) to the third photodetector (44), and the other guide mirror guides the absorption light output through the second reflector (35) to the second photodetector (43).

[0015] Furthermore, the guide mirror (27) is a prism, and a reflective film is coated on the reflective surface of the guide mirror (27).

[0016] An application of the aforementioned quantum chip as a sensing element in a quantum current transformer.

[0017] Compared with the prior art, the advantages of the present invention are: 1. The present invention can improve light intensity through an optical resonant loop. That is, the excitation light emitted from the first light source and the absorption light emitted from the second light source are both enhanced by resonance in the resonant loop. When the excitation light is enhanced by resonance, it can improve the excitation effect on the diamond NV color center (enhanced photofluorescence); when the absorption light is enhanced by resonance, it can improve the contrast of the intrinsic signal of the absorption light and enhance the absorption effect of the diamond NV color center on the absorption light.

[0018] 2. The optical resonant loop of this invention is constructed from a reflective mirror on one side of the diamond NV color center and two other mirrors. Therefore, the structure is simple, requires fewer optical components, and is easy to integrate and miniaturize. Furthermore, because this invention uses an optical resonant loop to enhance the resonance of the excitation and absorption light, it can enhance the excitation effect of the diamond NV color center and improve the contrast of the intrinsic signal of the absorption light without using a high-power laser as a light source, thus possessing the advantage of low energy consumption.

[0019] 3. This invention can switch between two measurement principles. When only the first light source is working, it realizes the magnetic measurement method based on the fluorescence generated by the stimulated diamond NV color center. When only the second light source is working, it realizes the magnetic measurement method based on the selective absorption of the absorbed light by the diamond NV color center. Furthermore, when the first light source and the second light source are working simultaneously, both magnetic measurement methods can be realized at the same time. Therefore, it has rich functions, strong verification, and can meet different measurement needs. 4. The present invention optimizes the structural design, thus the structure is simple, the manufacturing process is simple, and the size can be miniaturized, making it easy to integrate into the detection system.

[0020] 5. This invention is well-suited for power grid current measurement and can be used as a sensing element in existing electronic current transformers. Attached Figure Description

[0021] Figure 1 This is an overall structural diagram of an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the substrate structure of the sensing element in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the optical channel substrate structure according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the combined structure of the sensing element substrate and the optical channel substrate according to an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the sealing plate according to an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the device positions on the optical resonant loop in an embodiment of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, this embodiment discloses a quantum chip, which is a stacked structure, consisting of a carrier PCB1, a sensing element substrate 2, an optical channel substrate 3, and a cover plate 4 from bottom to top.

[0029] In this embodiment, the carrier PCB1 is a carrier printed circuit board that provides mechanical support and external electrical connection for the entire device.

[0030] like Figure 2 As shown, in this embodiment, the sensing element substrate 2 includes a first wafer 21. A microwave antenna 23 is etched on the top surface of the first wafer 21 near the front side, and a diamond NV color center 22 (a block diamond containing an ensemble NV color center) is attached to the microwave antenna 23.

[0031] On the top surface of the first wafer 21, heat sink windows are fabricated at the rear left and slightly right positions of the diamond NV color center 22. Each heat sink window houses a heat sink 25. The left heat sink 26 houses a first light source 24, and the right heat sink 26 houses a second light source 26. The first light source 24 outputs excitation light (green light, around 532nm), and the second light source 26 outputs absorption light (infrared light, wavelength 1042nm). The front side of the diamond NV color center 22 faces away from the area between the first light source 24 and the second light source 26, while the rear side faces the area between the first light source 24 and the second light source 26. The front side of the diamond NV color center 22 facing away from the area between the first light source 24 and the second light source 26 is coated with a mirror finish to create a reflective surface.

[0032] Furthermore, a guide mirror 27 is mounted on the top surface of the first wafer 21 next to the first light source 24, and another guide mirror is mounted on the top surface of the second wafer 21 next to the second light source 26. Both guide mirrors 27 are inclined in the vertical plane. The guide mirror 27 is a triangular prism, and a reflective film is coated on the reflective surface of the guide mirror 27.

[0033] In the sensing element substrate 2, the bottom surface of the first wafer 21 is bonded to the top surface of the carrier PCB1 through a eutectic bonding process.

[0034] like Figure 3 As shown, in this embodiment, the optical channel substrate 3 includes a second wafer 31, in which a central window 32, a color center window 33, and two guide-light source windows 34 are formed. The color center window 33 and the two guide-light source windows 34 are arranged in a triangle, with the color center window 33 in front and the two guide-light source windows 34 located to the left and right of the rear of the color center window 33, respectively. Furthermore, the color center window 33 and the two guide-light source windows 34 are connected to the central window 32, and all three—the color center window 33, the two guide-light source windows 34, and the central window 32—penetrate the optical channel substrate 3 in the vertical direction.

[0035] Each guide-light source window 34 is provided with a partition 341, which divides each guide-light source window 34 into two areas.

[0036] A first reflector 36 is mounted at the junction of the central window 32 and one of the guide-light source windows 34, and a second reflector 35 is mounted at the junction of the central window 32 and the other guide-light source window 34. The first reflector 36 and the second reflector 35 are designed to achieve efficient reflection and minimal transmission, thus achieving both efficient resonance and light output from the resonant loop. A temperature control element 37 is mounted in the central window 32, and an actuator 351 is provided at the junction of the central window 32 and at least one guide-light source window 34. The actuator 351 acts on the corresponding reflector, driving the corresponding reflector to move.

[0037] like Figure 3 , Figure 4As shown, in the optical channel substrate 3, the bottom surface of the second wafer 31 is bonded to the top surface of the first wafer 21 in the sensing element substrate 2 through a eutectic bonding process, so that the diamond NV color center 22 is placed in the color center window 33, the first light source 24 and the guide mirror 27 next to it are placed in different regions of the guide-light source window 34 corresponding to the first reflector 36, and the second light source 26 and the guide mirror next to it are placed in different regions of the guide-light source window corresponding to the second reflector 35. Thus, the first reflector 36 is located in the output light path of the first light source 24, the second reflector 35 is located in the output light path of the second light source 26, and the two guide mirrors 27 are located in the transmission light paths of the first reflector 36 and the second reflector 35, respectively. The first reflector 36, the second reflector 35, and the diamond NV color center form a triangular distribution, and the temperature control element 37 is located in the triangular region formed by the diamond NV color center 22, the first reflector 36, and the second reflector 35.

[0038] like Figure 6 As shown, in this embodiment, an optical resonant loop is formed by the first reflecting mirror 36, the second reflecting mirror 35, and the reflective surface of the front side of the diamond NV color center 22. By using the front side of the diamond NV color center 22 as a reflective surface to form the optical resonant loop, the number of reflecting mirrors can be reduced, and the structure can be optimized. The first light source 24 emits excitation light, and the second light source 26 emits absorption light. The excitation light enters the optical resonant loop from the first reflecting mirror 36, and the absorption light enters the optical resonant loop from the second reflecting mirror 35, where they resonate and enhance. The excitation light and absorption light are then output through the first reflecting mirror 36 and the second reflecting mirror 35, respectively. During this resonance process, both the excitation light and the absorption light can be trapped and cyclical multiple times in the optical resonant loop. During the cyclical process, both the excitation light and the absorption light pass through the diamond NV color center 22 and are reflected by the reflective surface of the diamond NV color center 22.

[0039] The placement of the first reflecting mirror 36, the second reflecting mirror 35, and the diamond NV color center 22 must satisfy the requirement of forming an optical resonant loop. The function of the optical resonant loop is to greatly enhance the interaction between light and the diamond NV color center 22. By trapping the light within it and circulating it hundreds or thousands of times, the weak magnetic signal is amplified to a level that can be clearly detected. The light emitted by the first light source 24 and the second light source 26 can resonate in the optical resonant loop.

[0040] The temperature control component 37 can be a thermoelectric cooler (TEC), a thermistor, etc. The temperature control component 37 senses and controls the temperature regulation to avoid measurement inaccuracies caused by temperature changes.

[0041] To meet the resonance condition, the position of the corresponding reflector can be adjusted by the actuator 351 (such as a piezoelectric material), thereby changing the optical path length and achieving resonance enhancement of the two types of light.

[0042] like Figure 5 As shown, in this embodiment, the cover plate 4 includes a third wafer 41, and three sensor windows 45 are formed on the bottom surface of the third wafer 41, which are arranged in a triangle. A first photodetector 42 is installed in the foremost sensor window 45, and a second photodetector 43 and a third photodetector 44 are installed in the two rear sensor windows, respectively. Furthermore, a filter is provided at at least one sensor window 45 corresponding to the position of the installed photodetector, and the filter is used to filter out stray light.

[0043] In the sealing plate 4, the bottom surface of the third wafer 41 is bonded to the top surface of the second wafer 31 in the optical channel substrate 3 via a eutectic bonding process. After bonding, the sensor window with the first photodetector 42 is aligned with the color center window 33 in the optical channel substrate 3, so that the first photodetector 42 faces the diamond NV color center 22. The sensor window with the second photodetector 43 is aligned with the corresponding area of ​​the guide mirror 27 in the guide-light source window where the second light source 26 is located, so that the second photodetector 43 faces the guide mirror 27 next to the second light source 26. The sensor window with the third photodetector 44 is aligned with the corresponding area of ​​the guide mirror in the guide-light source window where the first light source 24 is located, so that the third photodetector 44 faces the guide mirror next to the first light source 24. Furthermore, the solid portion of the sealing plate 4 encloses the area where the light source is located in each guide-light source window.

[0044] One of the guide mirrors 27 reflects the absorbed light output from the second reflector 35 upwards to the second photodetector 43, where the absorbed light is detected. Another guide mirror reflects the excitation light output from the first reflector 36 upwards to the third photodetector 44, where the excitation light is detected.

[0045] The preparation process in this embodiment is as follows: A microwave antenna 23 is etched on the first wafer 21, two heat sink windows are fabricated and heat sinks 25 are mounted on them respectively, a first light source 24 and a second light source 26 are mounted on the two heat sinks 25 respectively, a diamond NV color center 22 is mounted on the microwave antenna 23, and two guide mirrors 27 are mounted, thereby obtaining the sensing element substrate 2.

[0046] A central window 32, a color center window 33, and two guide-light source windows 34 are formed on the second wafer 31. A first reflector 36 is mounted at the connection between the central window 32 and one of the guide-light source windows 34. A second reflector 35 is mounted at the connection between the central window 32 and the other guide-light source window 34. A temperature control element 37 is mounted in the central window 32. An actuator 351 is mounted at the connection between the central window 32 and at least one guide-light source window 34. The actuator 351 acts on the corresponding reflector, thereby obtaining the light channel substrate 3.

[0047] Three sensor windows 45 are formed on the third wafer 41, and the filter, first photodetector 42, second photodetector 43 and third photodetector 44 are installed to obtain the cover plate 4.

[0048] The carrier PCB1, sensing element substrate 2, optical channel substrate 3, and cover plate 4 are bonded together by eutectic bonding process.

[0049] This embodiment can realize three magnetic measurement modes. When in use, some or all of the light sources can be activated for detection as needed. It is very suitable for power grid current measurement and can be used as a sensing element in existing quantum current transformers.

[0050] In this embodiment, when used as a sensing element in a quantum current transformer for measuring the current of a power grid bus, the current of the power grid bus generates a ring magnetic field in the surrounding space. This embodiment can accurately measure the magnetic field value and then calculate the corresponding current value of the power grid bus based on the magnetic field.

[0051] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. These embodiments are merely descriptions of preferred embodiments and are not intended to limit the scope or concept of the invention. The specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. Such combinations, as long as they do not violate the spirit of the present invention, should also be considered as part of this disclosure. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0052] This invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this invention and without departing from the design idea of ​​this invention, all modifications and improvements made by those skilled in the art to the technical solutions of this invention should fall within the protection scope of this invention. The technical content for which protection is sought in this invention has been fully described in the claims.

Claims

1. A quantum chip, characterized in that, include: The sensing element substrate (2) integrates a microwave antenna (23), a first light source (24), a second light source (26), and a diamond NV color center (22). The diamond NV color center (22) is attached to the microwave antenna (23). One side of the diamond NV color center (22) faces away from the area between the first light source (24) and the second light source (26), while the other side faces the area between the first light source (24) and the second light source (26). The side of the diamond NV color center (22) facing away from the area between the first light source (24) and the second light source (26) is set as a reflective mirror. The first light source (24) is used to output excitation light, and the second light source (26) is used to output absorption light. The optical channel substrate (3) integrates a first reflector (36) and a second reflector (35), which are tilted relative to each other. One side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), so that the first reflector (36), the second reflector (35), and the diamond NV color center form a triangular distribution. The first reflector (36) is located on the output optical path of the first light source (24), and the second reflector (35) is located on the output optical path of the second light source (26). The reflective surfaces of the first reflector (36), the second reflector (35), and the diamond NV color center (22) form an optical resonant loop. The excitation light and the absorption light can be trapped and circulated multiple times in the optical resonant loop. During the circulation, the excitation light and the absorption light pass through the diamond NV color center (22). The excitation light is output through the first reflector (36), and the absorption light is output through the second reflector (35). The sealing plate (4) integrates a first photodetector (42), a second photodetector (43), and a third photodetector (44). One side of the sealing plate (4) is connected to the other side of the light channel substrate (3). The first photodetector (42) is used to detect the fluorescence generated by the diamond NV color center (22) when it is excited. The second photodetector (43) is used to detect the absorbed light output through the second reflector (35). The third photodetector (44) is used to detect the excitation light output through the first reflector (36).

2. A quantum chip according to claim 1, characterized in that, The excitation light output by the first light source (24) is green light.

3. A quantum chip according to claim 1, characterized in that, The absorbed light output by the second light source (26) is infrared light.

4. A quantum chip according to claim 1, characterized in that, The sensing element substrate (2) also integrates two heat sinks, with the first light source (24) and the second light source (25) respectively disposed on the two heat sinks.

5. A quantum chip according to claim 1, characterized in that, The optical channel substrate (3) is provided with an actuator corresponding to at least one reflector position, and the position of the corresponding reflector is adjusted by the actuator.

6. A quantum chip according to claim 1, characterized in that, The optical channel substrate (3) also integrates a temperature control element (37). When one side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), the temperature control element (37) is located in the triangular region formed by the diamond NV color center (22), the first reflector (36), and the second reflector (35).

7. A quantum chip according to claim 1, characterized in that, The sensing element substrate (2) is bonded to the optical channel substrate (3), and the optical channel substrate (3) is bonded to the cover plate (4).

8. A quantum chip according to any one of claims 1-7, characterized in that, The sensing element substrate (2) also integrates two guide mirrors (27). When one side of the sensing element substrate (2) is connected to the other side of the optical channel substrate (3), the two guide mirrors (27) are located on the transmission light paths of the first reflector (36) and the second reflector (35), respectively. One of the guide mirrors (27) guides the excitation light output through the first reflector (36) to the third photodetector (44), and the other guide mirror guides the absorption light output through the second reflector (35) to the second photodetector (43).

9. A quantum chip according to claim 8, characterized in that, The guide mirror (27) is a prism, and a reflective film is coated on the reflective surface of the guide mirror (27).

10. An application of a quantum chip as a sensing element in a quantum current transformer as described in any one of claims 1-9.

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