MAGNETIC MEASUREMENT APPARATUS

• US 20150374250A1
• Filed: 06/24/2015
• Published: 12/31/2015
• Est. Priority Date: 06/26/2014
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: HATANO, Yuji, YAMADA, Koji, YOSHINO, Takashi
• Granted Patent: US 10,123,714 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/245 specially adapted for magnetoencephalographic [MEG] signals
• CPC Class Codes: C30B 29/04 Diamond
• CPC Class Codes: G01R 33/0094 Sensor arrays
• CPC Class Codes: G01R 33/032 using magneto-optic devices, e.g. Faraday or Cotton-Mouton effect
• CPC Class Codes: G01R 33/1284 Spin resolved measurements; Influencing spins during measurements, e.g. in spintronics devices G01R33/093 takes precedence; semiconductor devices using spin polarized carriers H01L29/66984

Abstract

High-accuracy magnetic measurement is performed by efficiently using nitrogen-vacancy pairs in all orientations. A magnetic measurement apparatus includes a diamond crystal and an image sensor. The diamond crystal has nitrogen-vacancy pairs. The image sensor detects the intensities of fluorescence generated by an exciting light applied to the diamond crystal by using a plurality of pixels. The nitrogen-vacancy pairs of the diamond crystal are made to one-to-one correspond to the pixels. The fluorescence generated by one nitrogen-vacancy pair is received by one pixel made to correspond to the nitrogen-vacancy pair.

Claims

1. A magnetic measurement apparatus comprising:

a diamond crystal having a plurality of nitrogen-vacancy pairs; and

an image sensor configured to detect a fluorescence intensity generated by an exciting light applied to the diamond crystal by using a plurality of pixels,

wherein the nitrogen-vacancy pairs of the diamond crystal are made to one-to-one correspond to the pixels, and fluorescence generated by one of the nitrogen-vacancy pairs is received by one of the pixels made to correspond to the nitrogen-vacancy pair.

2. The apparatus according to claim 1,

wherein a type of orientation of the vacancy of each of the nitrogen-vacancy pairs of the diamond crystal when viewed from the nitrogen thereof is specified with respect to an orientation of the diamond crystal.

3. The apparatus according to claim 2,

wherein the diamond crystal is a single crystal.

4. The apparatus according to claim 2, further comprising:

a microwave unit configured to irradiate the diamond crystal with microwaves based on an operation control signal; and

a signal processing unit configured to integrate differences between fluorescence intensities output from the pixels corresponding to the nitrogen-vacancy pairs which have the same orientation among the nitrogen-vacancy pairs whose orientations have been specified, when microwaves are applied from the microwave unit and when no microwaves are applied therefrom, and output the calculation result as a frequency correction value,

wherein the microwave unit modulates a frequency of microwaves to be applied based on the frequency correction value output from the signal processing unit.

5. The apparatus according to claim 4,

wherein the signal processing unit calculates the frequency correction value for each sensor block obtained by dividing the image sensor into a plurality of regions.

6. The apparatus according to claim 2, further comprising:

an irradiation unit configured to apply microwaves from a lower surface of the diamond crystal; and

a signal processing unit configured to integrate differences between fluorescence intensities output from the pixels corresponding to the nitrogen-vacancy pairs which have the same orientation among the nitrogen-vacancy pairs whose orientations have been specified, when microwaves are applied and when no microwaves are applied, and output the calculation result as a frequency correction value,

wherein the irradiation unit modulates a frequency of microwaves to be applied based on the frequency correction value output from the signal processing unit.

7. The apparatus according to claim 6,

wherein the irradiation unit comprises a plurality of high-frequency circuit portions,

the high-frequency circuit portions are provided in correspondence with blocks on the diamond crystal which are obtained by dividing the diamond crystal into a plurality of regions, and respectively modulate frequencies of microwaves to be applied based on the frequency correction values output from the signal processing unit, and

the signal processing unit integrates differences for each block on the image sensor which is obtained by dividing the image sensor into a plurality of regions, and outputs the calculation results as frequency correction values to the high-frequency circuit portions which apply the microwaves to blocks on the diamond crystal which correspond to blocks of the image sensor having undergone the integration.

8. The apparatus according to claim 7,

wherein operations of the high-frequency circuit portions are controlled based on operation control signals output from the signal processing unit, and

the signal processing unit controls the operation control signals so as not to make the adjacent high-frequency circuit portions simultaneously apply the microwaves.