Measuring device and measuring method

Abstract

The magnetic resonance component (1) is a component that is arranged in the measured AC physical field and can perform quantum operations in a specified quantum system. The coil (2) and the high-frequency power supply (3) apply a microwave magnetic field to the magnetic resonance component (1), the irradiation device (4) irradiates light to the magnetic resonance component (1), and the detection device (5) detects a physical phenomenon corresponding to the measured AC physical field from the magnetic resonance component (1); then, the measurement control unit (21) executes a specified number of DC physical field measurement sequences, determines the detection value of the physical phenomenon detected by the detection device (5) in each DC physical field measurement sequence, and the calculation unit (22) calculates the measurement result of a specific period of the measured AC physical field based on the detection value corresponding to the multiple DC physical field measurement sequences.

Description

Technical Field

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

[0002] A magnetic measurement device performs magnetic measurement by optically detected magnetic resonance (ODMR) using electron spin resonance (for example, see Patent Document 1).

[0003] In ODMR, for the excitation between spin sublevels and the excitation between optical transitions, a medium having energy levels of spin sublevels and energy levels of optical transitions is irradiated with a high-frequency magnetic field (microwave) and light, respectively, thereby detecting changes in the number of occupancy based on magnetic resonance between spin sublevels with high sensitivity using optical signals. Generally, electrons in the ground state emit red light when returning to the ground state after being excited by green light. For example, electrons in nitrogen and lattice defects (NVC; Nitrogen Vacancy Center) in the diamond structure, after being initialized by optical excitation by irradiation with a high-frequency magnetic field of about 2.87 GHz, transition from the lowest energy level (ms=0) among the three spin sublevels in the ground state to the energy level of the higher energy orbit (ms=±1) in the ground state. After being excited by green light, the electrons in this state return to the lowest energy level (ms=0) among the three sublevels in the ground state without radiation, so the amount of light emission decreases. Therefore, through this optical detection, it can be known whether magnetic resonance occurs by the high-frequency magnetic field. In ODMR, a light detection magnetic resonance material such as NVC is used.

[0004] In addition, as a method for measuring a DC magnetic field using NVC, there is a method using a Ramsey pulse sequence. In the Ramsey pulse sequence, (a) excitation light is irradiated to the NVC, (b) a first π / 2 pulse of microwaves is applied to the NVC, (c) a second π / 2 pulse of microwaves is applied to the NVC at a predetermined time interval tt from the first π / 2 pulse, (d) measurement light is irradiated to the NVC and the light emission of the NVC is measured, and (e) the magnetic flux density is estimated based on the measured light emission.

[0005] In addition, as a method for measuring an alternating magnetic field using NVC, there is a method for measuring using a spin echo pulse sequence. In the spin echo pulse sequence, (a) excitation light is irradiated to the NVC, (b) a first π / 2 pulse of microwaves is applied to the NVC at a phase of 0 degrees of the magnetic field to be measured, (c) a π pulse of microwaves is applied to the NVC at a phase of 180 degrees of the magnetic field to be measured, (d) a second π / 2 pulse of microwaves is applied to the NVC at a phase of 360 degrees of the magnetic field to be measured, (e) measurement light is irradiated to the NVC and the light emission of the NVC is measured, and (f) the magnetic flux density is estimated based on the measured light emission.

[0006] As described above, in the Ramsey pulse sequence or the spin echo pulse sequence, the magnetic field to be measured is inferred by utilizing the electron spin quantum operation based on the Rabi oscillation in the color center.

[0007] [Prior art literature]

[0008] [Patent Literature]

[0009] Patent Document 1: Japanese Patent, Tokukai Publication No. 2012-110489 Summary of the invention

[0010] However, in a spin echo pulse sequence, when the time interval between the first π / 2 pulse and the π pulse and the time interval between the π pulse and the second π / 2 pulse are longer than the spin coherence time that can preserve the information of the measured physical field, the information of the measured physical field will disappear. Therefore, it is difficult to accurately measure physical fields such as long-period alternating magnetic fields.

[0011] An object of the present invention is to obtain a measuring device and a measuring method capable of accurately measuring a long-period physical field by utilizing quantum operations in a predetermined quantum system.

[0012] The measuring device of the present invention comprises: a magnetic resonance component, which is arranged in an AC physical field to be measured and can perform quantum operations in a specified quantum system; a coil, which applies a microwave magnetic field to the magnetic resonance component; a high-frequency power supply, which conducts microwave current to the coil; an irradiation device, which irradiates light to the magnetic resonance component in a DC physical field measurement sequence; a detection device, which detects a physical phenomenon corresponding to the AC physical field to be measured from the magnetic resonance component in the DC physical field measurement sequence; a measurement control unit, which executes a specified number of DC physical field measurement sequences, controls the high-frequency power supply and the irradiation device in each DC physical field measurement sequence, and determines the detection value of the physical phenomenon detected by the detection device; and a calculation unit, which calculates the measurement result of a specific period portion of the measured AC physical field based on the detection value corresponding to the multiple DC physical field measurement sequences.

[0013] The measurement method involved in the present invention comprises: (a) executing a predetermined number of DC physical field measurement sequences, detecting a physical phenomenon corresponding to an AC physical field to be measured in each DC physical field measurement sequence, and determining a detection value of the physical phenomenon; and (b) calculating a measurement result of a specific period portion of the AC physical field to be measured based on the detection value corresponding to the multiple DC physical field measurement sequences.

[0014] Moreover, the DC physical field measurement sequence is performed using a magnetic resonance component, a coil, a high-frequency power supply, an irradiation device and a detection device, wherein the magnetic resonance component is configured in the measured AC physical field and is capable of performing quantum operations in a specified quantum system, the coil applies a microwave magnetic field to the magnetic resonance component, the high-frequency power supply conducts microwave current to the coil, the irradiation device irradiates light to the magnetic resonance component, and the detection device detects physical phenomena corresponding to the measured AC physical field from the magnetic resonance component.

[0015] (Effects of the Invention)

[0016] According to the present invention, it is possible to obtain a measuring device and a measuring method capable of accurately measuring a long-period physical field by utilizing quantum operations in a predetermined quantum system of a magnetic resonance member. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing the configuration of a measuring device according to an embodiment of the present invention.

[0018] Figure 2 Yes Description Figure 1 1 is a timing diagram of the operation of the measuring device shown in FIG.

[0019] Figure 3 Yes Description Figure 2 Timing diagram of the measurement sequence in . DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0021] Figure 1 It is a diagram showing the configuration of a measuring device according to an embodiment of the present invention. Figure 2 Yes Description Figure 1 2 is a timing chart showing the operation of the measuring device.

[0022] Figure 1The measuring device shown in has a magnetic resonance component 1. The magnetic resonance component 1 is a component that is arranged in the measured AC physical field and can perform quantum operations in a specified quantum system. Here, it includes a color center that can perform electron spin quantum operations. It should be noted that the color center included in the magnetic resonance component 1 can be one or multiple (i.e., ensemble). In the present embodiment, the quantum system is an electron spin, which can perform quantum operations based on Rabi oscillations. In addition, as the quantum system, atomic nuclear spins, magnetic flux quantum bits, etc. can also be used instead of electron spins. In this case, the magnetic resonance component 1 is a component that includes atomic nuclear spins that can perform quantum operations, or a component that can form magnetic flux quantum bits. In addition, in the present embodiment, the measured AC physical field is an AC magnetic field of a specific period, but it can also be other physical fields (electric fields, temperature fields, etc.) that alternate with a specific period. In addition, with respect to the measured AC physical field, it can be an AC physical field of a single frequency, or it can be an AC physical field with multiple frequency components.

[0023] In this embodiment, a light detecting magnetic resonance member is used as the magnetic resonance member 1, and a physical phenomenon corresponding to the measured alternating current physical field is optically detected in the magnetic resonance member 1 (in the case of the light detecting magnetic resonance member, it is fluorescent light emission). In addition, the physical phenomenon may be a change in electrical characteristics (such as a change in the resistance value of the magnetic resonance member 1), which can also be electrically detected.

[0024] Here, the light detecting magnetic resonance member used as the magnetic resonance member 1 is a plate material such as diamond having NVC (Nitrogen Vacancy Center), and is fixed to a support plate 1 a.

[0025] in addition, Figure 1 The measuring device shown in FIG. 1 includes a coil 2 , a high-frequency power supply 3 , an irradiation device 4 , and a detection device 5 .

[0026] The coil 2 applies a microwave magnetic field to the magnetic resonance member 1. The frequency of the microwave is set according to the type of the magnetic resonance member 1. For example, when the magnetic resonance member 1 is diamond having NVC, the coil 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) to the coil 2.

[0027] In the DC physical field measurement sequence, the irradiation device 4 irradiates the magnetic resonance member 1 with light (in the present embodiment, excitation light of a predetermined wavelength and measurement light of a predetermined wavelength).

[0028] In the DC physical field measurement sequence, the detection device 5 detects a physical phenomenon corresponding to the AC physical field to be measured from the magnetic resonance component 1 .

[0029] In the present embodiment, the detection device 5 is a light receiving device that detects fluorescence (the above-mentioned physical phenomenon) emitted from the magnetic resonance member 1 when the measurement light is irradiated. In addition, the detection device 5 may also be configured to include an electrode pair provided on the magnetic resonance member 1, and to detect the resistance value (the above-mentioned physical phenomenon) of the magnetic resonance member 1 that changes according to the measured AC physical field by measuring the current value flowing from the electrode pair to the magnetic resonance member 1.

[0030] Further, Figure 1 The measurement device shown in FIG. 1 includes a processing unit 11. The processing unit 11 includes, for example, a computer, and operates as various processing units by executing a program on the computer. In the present embodiment, the processing unit 11 operates as a measurement control unit 21 and a computing unit 22.

[0031] For example, Figure 2 As shown in the figure, the measurement control unit 21 performs the following processing: in each cycle PEj of the measured AC physical field (here, the measured AC magnetic field), a specified number of DC physical field measurement sequences SQi are executed (within a specific period within 1 cycle), and in each measurement sequence of the DC physical field measurement sequence SQ1, ..., SQn, the high-frequency power supply 3 and the irradiation device 4 are controlled to determine the detection value of the physical phenomenon detected by the detection device 5.

[0032] In addition, Figure 2 In the figure, a series of DC physical field measurement sequences SQ1, ..., SQn are started from the zero phase of the measured AC physical field, but a series of DC physical field measurement sequences SQ1, ..., SQn can also be started from any unknown phase.

[0033] In addition, in this embodiment, the time length of each DC physical field measurement sequence SQi and the time interval between DC physical field measurement sequences are fixed. In addition, the time interval between DC physical field measurement sequences can be zero or a predetermined time length other than zero.

[0034] For example, the irradiation device 4 includes a laser diode as a light source, and the detection device 5 includes a photodiode as a light receiving element. The measurement control unit 21 determines the light amount of the above-mentioned fluorescence as the above-mentioned detection value based on the output signal of the detection device 5 obtained by amplifying the output signal of the light receiving element.

[0035] Figure 3 Yes Description Figure 2 Timing diagram of the measurement sequence in .

[0036] In this embodiment, as the above-mentioned predetermined DC physical field measurement sequence SQi, for example, Figure 3The Ramsey pulse sequence shown in FIG.

[0037] In the present embodiment, the DC physical field measurement sequence SQi is a Ramsey pulse sequence, and therefore, the microwave includes two π / 2 pulses, and the physical phenomenon corresponds to the phase change of the electron spin of the color center (here, NVC) in free precession within the time interval tt between the two π / 2 pulses. Moreover, the time interval tt between the two π / 2 pulses can be set (a) based on the effective transverse relaxation time (free induction decay time) T2* of the magnetic resonance component 1, or (b) can be set so that the frequency of the AC physical field to be measured is included in the effective sensitivity frequency range obtained by the time interval tt (corresponding to the range below the upper limit frequency f of the time interval tt).

[0038] When the above time interval tt is approximately equal to half of the effective transverse relaxation time (free induction decay time) T2*, the sensitivity of the measured magnetic field in the measurement sequence SQi becomes better. In addition, the effective transverse relaxation time (free induction decay time) T2* has a value inherent to the color center used in the measurement. In addition, when the frequency of the measured AC physical field becomes lower (that is, the time of one cycle becomes longer), the number of measurement sequences SQi per cycle changes, or the interval between measurement sequences SQi changes.

[0039] Here, the sensitivity H is expressed as the product of dBmin (the minimum detectable magnetic field strength) and the square root of the measurement time Tm. Moreover, dBmin depends on T2* or the number of observed NVCs, etc. In the present embodiment, the above-mentioned DC physical field measurement sequence SQi is a Ramsey pulse sequence, and therefore, in the measurable frequency domain, the sensitivity H is approximately fixed regardless of the frequency of the measured AC magnetic field. Specifically, the lower the frequency component in the measured magnetic field, the longer the measurement time of each cycle, so that the number of measured values ​​in each specific period (here 1 cycle) increases, and therefore, the sensitivity is substantially fixed. In addition, when the number of measured values ​​in each specific period increases, the measured values ​​used in the curve fitting described later also increase, so that a more accurate fitting curve can be obtained.

[0040] The calculation unit 22 calculates the measurement result of the AC physical field to be measured based on the detection values ​​corresponding to the plurality of DC physical field measurement sequences.

[0041] In this embodiment, the computing unit 22 is, for example, Figure 2As shown in the figure, (a) in each of the multiple cycles of the measured AC physical field, the measurement value BMi of the measured AC physical field of one cycle is calculated based on the detection value corresponding to the above-mentioned multiple (n times) DC physical field measurement sequence SQ1~SQn, and (b) the average of the measurement values ​​of the measured AC physical field of one cycle, which is the same number as the multiple cycles, is calculated, thereby attenuating the noise in the measurement result of one cycle.

[0042] Specifically, by averaging in this way, other components other than the component of the frequency (and the frequency of integer multiples thereof) which is the reciprocal of the 1 cycle are attenuated, and thus the high-frequency and randomly generated noise is attenuated. In addition, even if it is a component of the frequency of integer multiples, when it is generated in a random phase, its component is also attenuated. For example, when it is Schottky noise, such temporal averaging is effective for the attenuation of noise. In addition, when the magnetic resonance component 1 is an ensemble, a spatially averaged detection value can be obtained, which is effective for the attenuation of noise.

[0043] For example, when the measurement value of the jth period (j=1,…,m) in m periods is set to BM1(j),…,BMn(j), the measurement results become [the average value of BM1(1) to BM1(m)],…,[the average value of BMn(1) to BMn(m)] after averaging.

[0044] Specifically, in the present embodiment, the calculation unit 22 calculates the measurement value BMi (i=1, . . . , n) of the intensity of the AC magnetic field to be measured for one cycle based on the above-mentioned fluorescence detection value obtained by the detection device 5 .

[0045] For example, the calculation unit 22 calculates the magnetic flux density from the detection value of the fluorescence according to the following formula.

[0046] Si=[(a+b) / 2]+[(ab) / 2]×cos(γ·BMi·tt)

[0047] Here, Si is the detection value of fluorescence in the i-th measurement sequence SQi (i.e., the corresponding phase i) within 1 cycle, BMi is the magnetic flux density in the i-th measurement sequence SQi (i.e., the corresponding phase i) within 1 cycle corresponding to the detection value Si, a and b are constants, tt is the time interval between two π / 2 pulses (free precession time), and γ is the gyromagnetic ratio (constant). In addition, a and b are the maximum and minimum values ​​of Si when BMi or tt is changed. For example, it can be determined by measuring Si when tt is changed relative to a known and fixed BMi in an experiment. In addition, a can also be obtained as the detection light amount when B=0.

[0048] Next, the operation of the magnetic field measurement device according to this embodiment will be described.

[0049] For example, Figure 2 As shown in , the measurement control unit 21 executes a predetermined number of times n (n>1) of DC physical field measurement sequences (here, Ramsey pulse sequences) SQ1, ..., SQn in each cycle (a specific period within 1 cycle (here, the entire cycle of 1 cycle)) of the measured AC physical field (here, AC magnetic field), and the operation unit 22 derives the DC physical field measurement values ​​BMi corresponding to each DC physical field measurement sequence SQi based on the detection values ​​of the detection device 5. In addition, here, the length of 1 cycle of the measured AC physical field (here, AC magnetic field) is known.

[0050] The measurement control unit 21 and the operation unit 22 continuously and repeatedly perform this action in multiple periods PE1, ..., PEm (m>1) of the measured AC physical field (here is the AC magnetic field) to determine the measurement values ​​[BM1(1), ..., BMn(1)], ..., [BM1(m), ..., BMn(m)] of multiple periods PE1, ..., PEm.

[0051] Then, the calculation unit 22 calculates the average value BMAi of the measurement values ​​BMi(1), ..., BMi(m) of multiple periods for each phase i within one period according to the following formula, and uses the calculation result [BMA1, ..., BMAn] as the measurement result.

[0052] BMAi=(BMi(1)+…+BMi(m)) / m

[0053] Here, the calculation unit 22 further performs curve fitting on the measurement results [BMA1, . . . , BMAn], and derives a fitting curve (that is, a measurement waveform of one cycle).

[0054] Here, when the function form of the fitting curve (e.g., a sine wave, etc.) is a known function form, for example, based on the above-mentioned measurement results, the optimal values ​​of the parameters in the function form are derived using the least squares method, thereby obtaining the function of the fitting curve.

[0055] In addition, when the functional form of the fitting curve is an unknown functional form, for example, interpolation (interpolation or extrapolation) is performed according to a predetermined method based on the above-mentioned measurement results, thereby obtaining the fitting curve.

[0056] Furthermore, the operation unit 22 derives the measurement result of the maximum amplitude of the measured AC physical field based on the fitting curve derived as described above. Figure 2 As shown in , the measured value (estimated value) of the maximum amplitude Bac of the measured alternating magnetic field of the sinusoidal wave is obtained.

[0057] Here, the Ramsey pulse sequence executed as each DC physical field measurement sequence SQi is described.

[0058] In a single Ramsey pulse sequence, for example, Figure 3 As shown in the figure, the measurement control unit 21 performs the following processing: (a) first, the magnetic resonance member 1 is irradiated with excitation light of a specified wavelength by the irradiation device 4 to prepare the state of the electron spin of the magnetic resonance member 1, (b) then, the magnetic field of a first π / 2 pulse of microwaves is applied to the magnetic resonance member 1 by the coil 2 and the high-frequency power supply 3, (c) then, after a specified time interval tt, the magnetic field of a second π / 2 pulse of microwaves is applied to the magnetic resonance member 1 by the coil 2 and the high-frequency power supply 3, (d) then, the measurement light for projection measurement is irradiated by the irradiation device 4, and the fluorescence emitted by the magnetic resonance member 1 is received by the detection device 5, and the amount of received light (detected light amount) is detected.

[0059] In addition, in the time interval tt, the direction of the electron spin changes proportionally to the time integral of the magnetic flux density of the external magnetic field (here the measured AC magnetic field). Therefore, the magnetic flux density of the external magnetic field (here the measured AC magnetic field) can be derived based on the detected light amount.

[0060] Furthermore, the time width tw of the π / 2 pulse is the time (about tens of nanoseconds) for rotating the electron spin by only π / 2, and is predetermined based on the period of the Rabi oscillation of the magnetic resonance component 1, etc. In addition, for example, the irradiation time of the excitation light and the irradiation time of the measurement light are about several microseconds to tens of microseconds, respectively. In addition, for example, the above-mentioned time interval tt is less than several hundred microseconds. In addition, the time interval between the excitation light irradiation and the first π / 2 pulse, and the time interval between the second π / 2 pulse and the measurement light irradiation, are preferably as short as possible.

[0061] In this embodiment, for example, Figure 3 As shown in , the Ramsey pulse sequence (DC physical field measurement sequence SQi) is continuously executed in one cycle of the measured AC magnetic field. Figure 3 In the embodiment, the irradiation of the measurement light in a certain measurement sequence SQi and the irradiation of the excitation light in the next measurement sequence SQ(i+1) are performed separately, but the two may be performed together.

[0062] Here, in a certain period PEj of the measured AC magnetic field, the i-th measurement sequence SQi is executed in a certain phase Pi (which may also be an unknown phase), and in the next period PE(j+1), the i-th measurement sequence SQi is also executed in the same phase Pi.

[0063] The measurement results obtained as described above are stored as data in a storage device (not shown), transmitted to an external device, or displayed on a display device.

[0064] In addition, for example, the length of the above-mentioned measurement sequence SQi is less than half a period of the measured AC physical field, for example, a low-frequency AC physical field below about 1 kHz (especially below about 100 Hz) becomes the measurement object.

[0065] In addition, in the case of the above-mentioned spin echo pulse sequence, the transverse relaxation time T2 of the electron spin is about 1 millisecond. When the measured AC magnetic field has a frequency component below about 1 kHz, it is usually difficult to accurately measure the magnetic field strength. However, in this embodiment, even in this case, the measured AC magnetic field has a frequency component below about 1 kHz, and the physical field can be measured well.

[0066] As described above, in the above embodiment, the magnetic resonance component 1 is a component that is arranged in the measured AC physical field and can perform quantum operations in a predetermined quantum system. The coil 2 applies a microwave magnetic field to the magnetic resonance component 1. The high-frequency power supply 3 conducts a microwave current to the coil 2. In the DC physical field measurement sequence, the irradiation device 4 irradiates light to the magnetic resonance component 1, and the detection device 5 detects a physical phenomenon corresponding to the measured AC physical field from the magnetic resonance component 1.

[0067] Then, the measurement control unit 21 executes a predetermined number of DC physical field measurement sequences, and in each DC physical field measurement sequence, controls the high frequency power supply 3 and the irradiation device 4 to determine the detection value of the physical phenomenon detected by the detection device 5. The calculation unit 22 calculates the measurement result of a specific period portion (here, one cycle portion) of the measured AC physical field based on the detection values ​​corresponding to the multiple DC physical field measurement sequences.

[0068] Thus, a long-period physical field such as an AC magnetic field can be accurately measured using quantum operations in a predetermined quantum system of the magnetic resonance device 1. Specifically, as described above, good sensitivity H in the low frequency region can be obtained, and thus the measured value of the physical field to be measured can be accurately obtained.

[0069] In addition, as described above, when the above-mentioned multiple DC physical field measurement sequences are uniformly executed (the length of the time interval tt in the DC physical field measurement sequence and the time interval of the DC physical field measurement sequence are set to a fixed value regardless of the phase of the measured AC physical field), the above-mentioned multiple DC physical field measurement sequences can also be performed without synchronizing the multiple DC physical field measurement sequences with the measured AC physical field. In addition, when it is a spin echo pulse sequence, it is necessary to synchronize with the measured AC magnetic field.

[0070] 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 the claims of this application.

[0071] For example, in the above-mentioned embodiment, as an example, the waveform of the measured AC magnetic field is assumed to be a sine wave, but the waveform of the measured AC magnetic field may also be other waveforms (triangular wave, sawtooth wave, rectangular wave, waveform synthesized from multiple waveforms, etc.), as long as the period of the measured AC magnetic field is a known period. In addition, the measured AC magnetic field may also have a DC component. Furthermore, when a physical field other than the AC magnetic field becomes the measurement object, the same is true.

[0072] In addition, in the above-mentioned embodiment, the time interval tt in the DC physical field measurement sequence can also be changed according to the phase within one cycle of the measured AC physical field. In this case, when there is an external AC signal that is known to be synchronized with the measured AC physical field, the phase of the measured AC physical field can also be determined according to the phase of the external AC signal. For example, when the measured AC physical field is generated due to a physical phenomenon originating from an external AC signal, the measured AC physical field is synchronized with the external AC signal. Or, for example, it can also be constructed as follows: after fixing the time interval tt, the above-mentioned DC physical field measurement sequence is repeatedly executed, and based on the measurement results obtained in multiple DC physical field measurement sequences, the waveform of the measured AC physical field and its phase are determined.

[0073] Furthermore, in the above-mentioned embodiment, as an example of a specific period, the measurement result of a portion of one cycle is obtained, but it can also be configured to obtain the measurement result of a period longer than one cycle (for example, a portion of two cycles, etc.). Further, in the above-mentioned embodiment, it can also be configured to obtain the measurement result of a period shorter than one cycle (that is, a specific phase range). In this case, for example, it can also be configured to obtain only the detection value corresponding to the period in each cycle in each cycle of the above-mentioned multiple cycles, and only the measurement value corresponding to the period is derived. However, the specific period is preferably one cycle.

[0074] Furthermore, in the above-mentioned embodiment, when the intensity (amplitude) of the measured physical field is large, and during the above-mentioned time interval tt, the electron spin of the color center in the magnetic resonance component 1 rotates more than one revolution (2π), a detection value, a measurement value, and a measurement result corresponding to the angle of the remainder when the actual rotation angle of the electron spin is divided by 2π can be obtained. Therefore, in this case, the operation unit 22 infers the actual rotation angle of the electron spin based on the above-mentioned detection value, measurement value, or measurement result, converts the detection value, measurement value, or measurement result into a value corresponding to the actual rotation angle of the electron spin, and performs the above-mentioned curve fitting based on the converted value. In addition, at this time, it can also be configured as follows: without performing this conversion, the above-mentioned curve fitting is performed directly using a fitting function that takes into account the 2π spin phase period.

[0075] Furthermore, in the above-mentioned embodiment, when all the measurement values ​​BMi(1), ..., BMi(m) of multiple (m) periodic parts associated with a certain phase i are derived, the average value BMi of the m measurement values ​​BMi(1), ..., BMi(m) associated with phase i becomes the part of the phase i in the measurement result, but when there is no measurement value BMi(1), ..., BMi(m) of a part of the multiple (m) periodic parts associated with a certain phase i, and thus only the remaining part of BMi(1), ..., BMi(m) is derived, the average value of the remaining part is calculated as the above-mentioned average value BMi. That is, for example, when the Lth (Lth period) measurement value BMi among the m measurement values ​​BMi(1), ..., BMi(L-1), BMi(L), BMi(L+1), ..., BMi(m) (1<L-1, L, L+1<m) cannot be obtained (for example, when the corresponding detection value cannot be obtained as an appropriate value, when the Lth measurement is not performed, etc.), the average value of the remaining (m-1) measurement values ​​is calculated as the above-mentioned average value BMi according to the following formula. In addition, the same is true when more than two measurement values ​​cannot be obtained.

[0076] BMAi=(BMi(1)+…+BMi(L-1)+BMi(L+1)+…+BMi(m)) / (m-1)

[0077] Furthermore, in the above-mentioned embodiment, the measurement values ​​of specific periods of multiple cycle parts are averaged in each phase to obtain the measurement result. However, when time averaging is not required, the measurement values ​​of specific periods of one cycle part (without averaging) can also be used as the measurement result.

[0078] (Industrial Applicability)

[0079] The present invention can be applied to, for example, a magnetic measuring device and a magnetic measuring method.

Claims

1. A measuring device, characterized in that: have: A magnetic resonance component, which is arranged in the measured AC physical field and is capable of performing quantum operations in a specified quantum system, a coil for applying a microwave magnetic field to the magnetic resonance member, a high frequency power supply, which conducts the microwave current to the coil, an irradiation device, which irradiates light to the magnetic resonance member in a DC physical field measurement sequence, a detection device, which detects a physical phenomenon corresponding to the measured AC physical field from the magnetic resonance member in the DC physical field measurement sequence, a measurement control unit that executes a predetermined number of the DC physical field measurement sequences, controls the high frequency power supply and the irradiation device in each of the DC physical field measurement sequences, determines a detection value of the physical phenomenon detected by the detection device, and a calculation unit for calculating the measurement result of the specific period portion of the measured AC physical field based on the detection values ​​corresponding to the plurality of DC physical field measurement sequences; The calculation unit executes the DC physical field measurement sequence a specified number of times in each cycle of the measured AC physical field, and calculates the average of the measurement results of the specific period portion obtained for multiple cycles of the measured AC physical field, thereby attenuating the noise in the measurement results of the specific period portion, wherein the number of the measurement results is the same as the number of the multiple cycles.

2. The measuring device according to claim 1, characterized in that The magnetic resonance member comprises a color center capable of performing electron spin quantum manipulation, The DC physical field measurement sequence, as the microwave contains two π / 2 pulses, The physical phenomenon corresponds to the phase change of the electron spin of the color center in free precession in the time interval between the two π / 2 pulses in the Rabi oscillation, The time interval between the two π / 2 pulses is (a) set according to the effective transverse relaxation time of the magnetic resonance component, and (b) set so that the frequency of the measured AC physical field is included in the effective sensitivity frequency range obtained by the time interval.

3. A measurement method, characterized in that: include: (a) executing a predetermined number of DC physical field measurement sequences, in each of which a physical phenomenon corresponding to the measured AC physical field is detected and a detection value of the physical phenomenon is determined; (b) calculating the measurement result of a specific period portion of the measured AC physical field based on the detection values ​​corresponding to the plurality of DC physical field measurement sequences; The DC physical field measurement sequence is performed using a magnetic resonance component, a coil, a high-frequency power supply, an irradiation device, and a detection device. in, The magnetic resonance component is arranged in the measured AC physical field and is capable of performing quantum operations in a predetermined quantum system. The coil applies a microwave magnetic field to the magnetic resonance member. The high frequency power supply causes the microwave current to flow through the coil. The irradiation device irradiates the magnetic resonance member with light. The detection device detects the physical phenomenon corresponding to the measured AC physical field from the magnetic resonance member; In each cycle of the measured AC physical field, the DC physical field measurement sequence is executed a specified number of times, and the average of the measurement results of the specific period portion obtained for the multiple cycles of the measured AC physical field is calculated, thereby attenuating the noise in the measurement results of the specific period portion, wherein the number of the measurement results is the same as the number of the multiple cycles.

Images