Measuring device

Abstract

The measuring device of the present invention can perform magnetic field measurement or electric field measurement using electronic spin quantum manipulation based on Rabi oscillation in a relatively short time, wherein the electronic spin quantum manipulation based on Rabi oscillation is performed by microwave irradiation; a microwave generating unit (2) generates microwaves for performing electronic spin quantum manipulation based on Rabi oscillation, and an observation system (11) determines the intensity of the measured field using an electron spin resonance component irradiated with the microwaves; the microwave generating unit (2) comprises a coil unit (2a) for emitting the microwaves and an additional electrostatic capacitor unit (2b) electrically connected in parallel with the coil unit (2a); and the additional electrostatic capacitor unit (2b) is directly arranged relative to the coil unit (2a), or is arranged between an electrical element electrically connected to the coil unit (2a) and the coil unit (2a).

Description

Technical Field

[0001] The invention relates to a measuring device. Background Art

[0002] In one magnetic measurement device, magnetic field measurement is performed by optically detected magnetic resonance (ODMR) using electron spin resonance (for example, refer to Patent Document 1).

[0003] In ODMR, a high-frequency magnetic field (microwave) and light are irradiated to an electron spin resonance element having a sub-level and an optical transition level, thereby detecting changes in the occupancy number due to inter-sub-level magnetic resonance with high sensitivity using an optical signal.

[0004] For example, in nitrogen and lattice defects (NVC: Nitrogen Vacancy Center) in the diamond structure, usually, the ground state electron emits red light when it returns to the ground state after being excited by green light. On the other hand, by irradiating a high-frequency magnetic field of about 2.87GHz, the electron transitions from the lowest level (ms=0) of the three levels in the ground state to the remaining high-energy level (ms=±1). When the electron of the secondary level (ms=±1) is excited by green light, it returns to the secondary level (ms=0) in the ground state in a non-radiative state, so the amount of light emission decreases.

[0005] Furthermore, the secondary (ms=±1) of the high energy level changes due to the Zeeman effect based on the measured magnetic field and the Stark effect based on the measured electric field. Since the amount of fluorescence observed by ODMR decreases at the microwave frequency corresponding to the changed secondary (ms=±1), the intensity of the measured field is determined by measuring the distribution of the fluorescence.

[0006] [Prior art literature]

[0007] [Patent Literature]

[0008] Patent Document 1: Japanese Patent, Japanese Patent Application Publication No. 2012-110489

[0009] This is not limited to ODMR. For example, when it is desired to perform spin quantum manipulation in a relatively short time using the measurement system described above, the intensity of microwaves needs to be increased, wherein the measurement system performs spin quantum manipulation based on Rabi oscillation (for example, the above-mentioned transition between secondary electron spins) by irradiating microwaves. That is, in order to shorten the measurement time of the magnetic field, the intensity of microwaves needs to be increased. However, according to the above-mentioned magnetic measurement device, it is difficult to increase the intensity of microwaves. Furthermore, it is difficult to measure the magnetic field in a relatively short time. Summary of the invention

[0010] The present invention is completed in view of the above-mentioned problems, and its purpose is to obtain a measuring device that can perform magnetic field measurement or electric field measurement in a short time using electron spin quantum manipulation based on Rabi oscillation, wherein the electron spin quantum manipulation based on Rabi oscillation is performed by microwave irradiation.

[0011] The measuring device of the present invention comprises: a microwave generating unit, which generates microwaves for performing electron spin quantum manipulation based on Rabi oscillation; and an observation system, which determines the intensity of the measured field using an electron spin resonance component irradiated with the microwaves. The microwave generating unit comprises a coil unit for emitting the microwaves and an additional electrostatic capacitor unit electrically connected in parallel with the coil unit. Moreover, the additional electrostatic capacitor unit is directly arranged relative to the coil unit, or is arranged between an electrical element electrically connected to the coil unit and the coil unit.

[0012] (Effects of the Invention)

[0013] According to the present invention, a measuring device can be obtained that can perform magnetic field measurement or electric field measurement in a relatively short time using quantum manipulation of electron spins based on Rabi oscillation by microwave irradiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram showing the structure of a measuring device according to a first embodiment of the present invention.

[0015] Figure 2 Yes Figure 1 This is a block diagram for explaining an example of circuits around the microwave generating unit 2 and the high-frequency power supply 3 in the measuring device shown in FIG.

[0016] Figure 3A is a front view of the microwave generating unit 2 in the first embodiment, Figure 3B It is a side view of the microwave generating unit 2 in the first embodiment.

[0017] Figure 4 Yes means Figure 1 A circuit diagram of an equivalent circuit of the microwave generating unit 2 in the measuring device shown.

[0018] Figure 5 yes Figure 3A and Figure 3B An expanded view of the microwave generating unit 2 is shown in FIG.

[0019] Figure 6 This is a diagram for explaining the enhancement of the magnetic induction intensity of microwaves according to the example of the microwave generating unit 2 in the first embodiment.

[0020] Figure 7This is a diagram showing an example of the microwave generating unit 2 in the measuring device according to the second embodiment.

[0021] Figure 8 This is a diagram for explaining the magnetic flux density distribution according to the example of the microwave generating unit 2 in the second embodiment.

[0022] Fig. 9 This is a diagram showing an example of the microwave generating unit 2 in the measuring device according to the third embodiment.

[0023] Fig.10 This is a diagram showing an example of the microwave generating unit 2 in the measuring device according to the fourth embodiment.

[0024] Fig.11 This is a diagram (1 / 2) showing an example of the microwave generating unit 2 in the measuring device according to the fifth embodiment.

[0025] Fig.12 FIG. 2 is a diagram ( 2 / 2 ) showing an example of the microwave generating unit 2 in the measuring device according to the fifth embodiment.

[0026] (Explanation of symbols)

[0027] 1 Electron spin resonance components

[0028] 2 Microwave generation unit

[0029] 2a Coil section

[0030] 2b Adding electrostatic capacitor

[0031] 2c Electrode sheet

[0032] 2e Electrostatic Capacitor Components

[0033] 11 Observation system DETAILED DESCRIPTION

[0034] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0035] [Implementation Method 1]

[0036] Figure 1 1 is a diagram showing a configuration of a measuring device according to Embodiment 1 of the present invention. As an example, the measuring device according to Embodiment 1 measures the intensity of a magnetic field or an electric field using an optically detected magnetic resonance method. Figure 1The measuring device shown in the figure has an electron spin resonance component 1. The electron spin resonance component 1 is arranged in a measured field (a measured magnetic field or a measured electric field). As described later, the electron spin resonance component 1 is subjected to electron spin quantum manipulation based on Rabi oscillation in a predetermined measurement sequence.

[0037] It should be noted that the measurement method of the measured field is not limited to the optical detection magnetic resonance method, and other methods can also be used as long as they utilize electron spin quantum manipulation based on Rabi oscillation.

[0038] In this embodiment, the electron spin resonance member 1 is a plate of diamond or the like having NVC for optical detection of magnetic resonance and is fixed to the support plate 1a. It should be noted that the electron spin resonance member 1 for optical detection of magnetic resonance is not limited to diamond having NVC, but may be a member having other color centers.

[0039] Figure 1 The measuring device shown in FIG. 1 includes a microwave generating unit 2 and a high-frequency power source 3 .

[0040] The microwave generating unit 2 generates microwaves for performing quantum manipulation of electron spins in the electron spin resonance element 1 based on Rabi oscillation.

[0041] In the first embodiment, the microwave generating unit 2 applies a microwave magnetic field to the electron spin resonance component 1. The frequency of the microwave is set according to the type of the electron spin resonance component 1. For example, when the electron spin resonance component 1 is diamond having NVC, the microwave generating unit 2 applies a microwave magnetic field of about 2.87 GHz. The high frequency power supply 3 conducts a microwave current (i.e., a current for generating the above-mentioned microwave magnetic field) in the microwave generating unit 2.

[0042] and then, Figure 1 The measuring device shown in FIG. 1 includes an irradiation device 4, a light receiving device 5, a calculation processing device 6, etc. as an observation system 11. The observation system 11 determines the intensity of the field to be measured using the electron spin resonance device 1 irradiated with the microwave.

[0043] The irradiation device 4 irradiates light (excitation light of a predetermined wavelength and measurement light of a predetermined wavelength) to the electron spin resonance element 1. The light receiving device 5 detects fluorescence emitted from the electron spin resonance element 1 when the measurement light is irradiated.

[0044] The calculation processing device 6 includes, for example, a computer, and operates as various processing units by executing programs on the computer. In this embodiment, the calculation processing device 6 operates as a measurement control unit 6a and a measurement target intensity calculation unit 6b.

[0045] The measurement control unit 6a performs a predetermined measurement sequence on the measured field, in which the high frequency power supply 3 and the irradiation device 4 are controlled, and the detection light amount of the fluorescence detected by the light receiving device 5 is determined. For example, the irradiation device 4 includes a laser diode as a light source, and the light receiving device 5 includes a photodiode as a light receiving element. The measurement control unit 6a determines the above-mentioned detection light amount based on the output signal of the light receiving device 5 obtained by amplifying the output signal of the light receiving element. In this embodiment, as the above-mentioned predetermined measurement sequence, a Ramsey pulse sequence, a spin echo sequence, etc. can be used, but it is not limited to this.

[0046] The measurement target intensity calculation unit 6 b calculates the intensity of the field to be measured (for example, the amplitude of the magnetic flux density) from the above-mentioned detection light amount according to a predetermined calculation formula.

[0047] Figure 2 Yes Figure 1 This is a block diagram for explaining an example of circuits around the microwave generating unit 2 and the high-frequency power supply 3 in the measuring device shown in FIG.

[0048] For example, Figure 2 As shown in the figure, the high-frequency power source 3 is electrically connected to the substrate 31 by the transmission line portion 21, and the microwave generating portion 2 is mounted on the substrate 31, whereby the high-frequency power source 3 conducts microwave current to the microwave generating portion 2 via the transmission line portion 21 and the substrate 31 (i.e., the wiring pattern on the substrate 31) relative to the microwave generating portion 2. In addition, the frequency adjusting portion 22, the impedance matching portion not shown, etc. are electrically connected in series to the microwave generating portion 2. In addition, the frequency adjusting portion 22, the impedance matching portion not shown, etc. are mounted on the substrate 31. The frequency adjusting portion 22 is, for example, a series LC circuit.

[0049] Figure 3A and Figure 3B Each of them is a diagram showing an example of the microwave generating unit 2 in the measuring device according to the first embodiment. Figure 3A is a front view of the microwave generating unit 2 in the first embodiment, Figure 3B It is a side view of the microwave generating unit 2 in the first embodiment.

[0050] The microwave generating unit 2 includes a substantially circular coil unit 2 a for radiating microwaves and an additional electrostatic capacitor unit 2 b arranged electrically in parallel with the coil unit 2 a .

[0051] The coil portion 2a is in a state of sandwiching the electron spin resonance component 1, or in a state of being located on one side of the electron spin resonance component 1, and conducts two currents that are parallel to each other at a predetermined interval, thereby emitting the above-mentioned microwaves. The coil portion 2a can be two linear coils or a plate-shaped coil. It should be noted that even if the coil portion 2a is a plate-shaped coil, the microwave current flows through the end surface portion of the coil portion 2a due to the skin effect, thereby forming two currents.

[0052] In the first embodiment, Figure 3A and Figure 3B As shown in FIG. 1 , the coil portion 2a is a plate-shaped coil.

[0053] In the first embodiment, the microwave generating unit 2 (coil unit 2a) is as follows: Figure 3B It should be noted that the microwave generating unit 2 (coil unit 2a) may also be installed on the end of the substrate 31 as shown by the solid line in FIG. Figure 3B It is mounted on the end of the substrate 31 as shown by the dotted line in FIG.

[0054] Figure 4 Yes means Figure 1 A circuit diagram of an equivalent circuit of the microwave generating unit 2 in the measuring device shown.

[0055] The additional electrostatic capacitor 2b is provided to enhance the output of microwaves. Figure 4 As shown in , it is arranged in parallel with the coil portion 2a and adds electrostatic capacitance to the coil portion 2a. It should be noted that the additional electrostatic capacitance portion 2b is intentionally provided as a portion having a predetermined electrostatic capacitance rather than stray electrostatic capacitance.

[0056] Here, the frequency adjustment unit 22 is provided to adjust the frequency of the microwaves to a desired frequency, thereby making it possible to suppress the frequency change of the microwaves caused by the additional electrostatic capacitance unit 2b.

[0057] The additional electrostatic capacitor 2b is disposed directly with respect to the coil portion 2a, or disposed between an electrical element (the frequency adjustment portion 22, impedance matching portion, etc.) electrically connected to the coil portion 2a and the coil portion 2a.

[0058] In the first embodiment, the additional electrostatic capacitor 2b is directly arranged relative to the coil portion 2a (as a whole, or as a separate body connected to each other), and has a pair of electrode sheets 2c extending from the coil portion 2a. The electrode sheet 2c has a flat plate portion that extends a predetermined length from the end of the coil portion 2a in a substantially circumferential direction and then bends substantially vertically to the outside of the coil portion 2a. The electrostatic capacitance of the additional electrostatic capacitor 2b is set according to the gap width and area of ​​the flat plate portion.

[0059] Furthermore, if Figure 3A and Figure 3B As shown in FIG. 1 , the microwave generating portion 2 includes a pair of connecting leg portions 2 d extending from both ends of the coil portion 2 a.

[0060] Figure 5 yes Figure 3A and Figure 3B The expanded view of the microwave generating unit 2 is shown in FIG. Figure 5 As shown in FIG. 1 , the coil portion 2a and the pair of electrode pieces 2c (and the pair of connecting legs 2d) are obtained by molding a single conductive plate.

[0061] Next, the operation of the measuring device according to the first embodiment will be described.

[0062] The measurement control unit 6a performs the following processing according to a predetermined measurement sequence.

[0063] (a) First, the electron spin resonance member 1 is irradiated with excitation light of a predetermined wavelength by the irradiation device 4 to form a state of electron spins in the electron spin resonance member 1;

[0064] (b) Then, the microwave generating unit 2 and the high-frequency power supply 3 are used to apply pulsed microwaves of a predetermined timing and a predetermined time width to the electron spin resonance element 1;

[0065] (c) Then, the irradiation device 4 irradiates the measurement light for projection measurement, the light receiving device 5 receives the fluorescence emitted by the electron spin resonance element 1 and detects the received light quantity (detected light quantity), and the measured object intensity calculation unit 6b calculates the intensity of the measured field based on the detected light quantity.

[0066] In such a measurement sequence, when the microwave generation unit 2 generates microwaves, energy W accumulated in the microwave generation unit 2 is expressed by the following equation.

[0067] W=Wh+We

[0068] Here, Wh is the magnetic energy stored in the coil portion 2a, and is proportional to the inductance L of the coil portion 2a. Also, We is the electric energy stored in the additional electrostatic capacitance portion 2b, and is proportional to the electrostatic capacitance C of the additional electrostatic capacitance portion 2b.

[0069] Wh and We alternate at the same frequency corresponding to the frequency of the microwave and at a phase difference of approximately 90 degrees. The larger W is, the higher the intensity of the microwave is. Therefore, the intensity of the microwave is enhanced by adding the electrostatic capacitor 2b.

[0070] Furthermore, by increasing the intensity of microwaves, electron spin quantum manipulation can be performed in a short time, thereby shortening the time required for magnetic field measurement or electric field measurement.

[0071] As described above, according to the above-mentioned embodiment 1, the microwave generating unit 2 generates microwaves for performing electron spin quantum manipulation based on Rabi oscillation. The observation system 11 determines the intensity of the measured field using the electron spin resonance component irradiated with the microwave. The microwave generating unit 2 includes a coil portion 2a for emitting the above-mentioned microwaves and an additional electrostatic capacitor portion 2b electrically connected in parallel with the coil portion 2a. Moreover, the additional electrostatic capacitor portion 2b is directly configured relative to the coil portion 2a, or is configured between an electrical element electrically connected to the coil portion 2a and the coil portion 2a.

[0072] As a result, the microwave output is enhanced, so that magnetic field measurement or electric field measurement using electron spin quantum manipulation based on Rabi oscillation by microwave irradiation can be performed in a shorter time.

[0073] Figure 6 This is a diagram for explaining the enhancement of the magnetic induction intensity of microwaves according to the example of the microwave generating unit 2 in the first embodiment. Figure 6 The figure shows the simulation results when the radius of the coil part 2a is 2.0 mm, the width of the coil part 2a (the width of the plate-shaped coil) is 1.5 mm, and the frequency adjustment part 22 is used to make the microwave frequency close to 2.85 GHz. Figure 6 As shown in , the average magnetic flux density of the coil part 2a is increased by adding the electrostatic capacitor 2b compared to when the additional electrostatic capacitor 2b is not provided. It should be noted that the standardized average magnetic flux density is the intensity after the average magnetic flux density is standardized by using the reflection loss.

[0074] [Implementation Method 2]

[0075] Figure 7 1 is a diagram showing an example of a microwave generating unit 2 in a measuring device according to Embodiment 2. In Embodiment 2, the additional electrostatic capacitor 2b includes an electrostatic capacitor element 2e electrically connected to the coil 2a. The electrostatic capacitor element 2e is, for example, a small chip capacitor, and two terminals of the electrostatic capacitor element 2e are electrically and mechanically connected to a pair of terminal pieces 2f extending from the end of the coil 2a in a substantially circumferential direction.

[0076] It should be noted that other structures and operations of the measuring device according to the second embodiment are the same as those of the first embodiment, and therefore, description thereof will be omitted.

[0077] Figure 8 This is a diagram for explaining the magnetic flux density distribution according to the example of the microwave generating unit 2 in the second embodiment. Figure 8 The simulation results of magnetic flux density distribution are shown in FIG. Figure 8 As shown in FIG. 1 , the gap 2g at the end of the circular coil portion 2a is narrowed by the terminal piece 2f, and the distribution of the magnetic flux density in the circumferential direction is uniformed.

[0078] [Implementation Method 3]

[0079] Fig. 9 1 is a diagram showing an example of a microwave generating unit 2 in a measuring device according to Embodiment 3. In Embodiment 3, the coil unit 2a has two linear coils. It should be noted that in Embodiment 3, the two linear coils in the coil unit 2a have a common (one) additional electrostatic capacitor unit 2b, but it may also be configured such that the two linear coils in the coil unit 2a each have (i.e., two) additional electrostatic capacitor units 2b.

[0080] It should be noted that the other configurations and operations of the measuring device according to the third embodiment are the same as those of the first embodiment, and therefore, the description thereof is omitted. In the third embodiment, the additional electrostatic capacitor 2b may be configured the same as that of the second embodiment.

[0081] [Implementation method 4]

[0082] Fig.10 This is a diagram showing an example of a microwave generating unit 2 in a measuring device according to a fourth embodiment. In the fourth embodiment, the coil portion 2a is formed as two parallel wiring patterns (metal patterns) 2-1 and 2-2 on the surface and back surface of a substrate 31 having a specified thickness. In addition, a through hole 31a is provided on the substrate 31, which passes through the center of the coil portion 2a. It should be noted that when the substrate 31 is a multi-layer substrate, it can also be configured such that the coil portion 2a is formed as two parallel wiring patterns (metal patterns) in different layers in the multi-layer substrate. Fig.10 Although the additional electrostatic capacitor 2b is not shown in the figure, the additional electrostatic capacitor 2b is also provided in the same manner. For example, an electrostatic capacitor element similar to the electrostatic capacitor element 2e is mounted on the substrate 31 and is electrically connected to the coil portion 2a.

[0083] It should be noted that the other structures and operations of the measuring device according to the fourth embodiment are the same as those of the first or second embodiment, and therefore, the description thereof will be omitted.

[0084] [Implementation method five]

[0085] Fig.11 and Fig.12 Each of them is a diagram showing an example of a microwave generating unit 2 in a measuring device according to a fifth embodiment. In the fifth embodiment, a through hole 31a is provided on a substrate 31 having a predetermined thickness, and a coil unit 2a as a plate-shaped coil is arranged in the through hole 31a. Fig.11 In the example shown, the through hole 31a is formed in a cylindrical shape, and the coil portion 2a contacts the inner wall of the through hole 31a. Fig.12 In the example shown, the through hole 31a is formed in a square cylindrical shape, and the coil portion 2a does not contact the inner wall of the through hole 31a. Fig.11 and Fig.12 Although the additional electrostatic capacitor 2b is not shown in the figure, the additional electrostatic capacitor 2b is also provided in the same manner.

[0086] It should be noted that other structures and operations of the measuring device involved in the fifth embodiment are the same as those in the first or second embodiment, and therefore, the description thereof is omitted.

[0087] It should be noted that various changes and modifications may be made to the above-mentioned embodiments without departing from the spirit and scope of the subject matter and without diminishing the intended advantages. Since these changes and modifications are obvious to those skilled in the art, these changes and modifications should also be included in the scope of protection of the claims of this application.

[0088] For example, in the above-described embodiment, the electrostatic capacitance element 2e as the additional electrostatic capacitance portion 2b may be mounted on the substrate 31 (that is, the wiring pattern of the substrate 31).

[0089] Furthermore, in the above-described embodiment, the measurement target intensity calculation unit 6 b determines the magnetic field intensity of the measured field as an example, but may also determine the electric field intensity of the measured field.

[0090] (Industrial Applicability)

[0091] The present invention can be applied, for example, to a measuring device using optical detection of magnetic resonance.

Claims

1. A measuring device, characterized in that: have: a microwave generating unit for generating microwaves for performing electron spin quantum manipulation based on Rabi oscillation, an observation system for determining the intensity of a measured magnetic field or a measured electric field as a measured field using an electron spin resonance member irradiated with the microwaves; The microwave generating unit comprises: a coil portion which emits the microwave, an additional electrostatic capacitor portion which is electrically arranged in parallel with the coil portion and has a pair of electrode sheets extending from the coil portion; a pair of connecting legs extending from both ends of the coil portion; The additional electrostatic capacitance unit is disposed directly with respect to the coil unit, or is disposed between an electrical element electrically connected to the coil unit and the coil unit.

2. The measuring device according to claim 1, characterized in that The coil portion, the pair of electrode pieces, and the pair of connecting legs are formed by molding one conductive plate.

3. The measuring device according to claim 1 or 2, characterized in that The measuring device further includes a frequency adjustment unit electrically arranged in series with the microwave generating unit. The frequency adjustment unit adjusts the frequency of the microwave to a desired frequency so as to suppress a frequency change of the microwave caused by the additional electrostatic capacitance unit.

4. The measuring device according to claim 1 or 2, characterized in that The coil unit radiates microwaves by conducting two currents that are parallel to each other with a predetermined interval therebetween in a state of sandwiching the electron spin resonance element or being located on one side of the electron spin resonance element.

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