Diamond nitrogen-vacancy center-based magnetic field detection device and method for manufacturing the same

Abstract

The present invention relates to a magnetic field detection device using a diamond nitrogen-void center and a method for manufacturing the same, comprising: an optical fiber; a diamond beam joined to the optical fiber and for transmitting laser light of the optical fiber; a cone member made of diamond material connected to the end of the diamond beam and having the shape of an inverted cone; and an optical signal emitting part formed of a diamond nitrogen-void center provided at the tip of the cone member and emitting an optical signal for magnetic field measurement as the laser light reaches it.

Description

Technology Field

[0001] The present invention relates to a magnetic field detection device for detecting a magnetic field using a diamond nitrogen-void center and a method for manufacturing the same. Background Technology

[0003] Magnetic fields have been the subject of measurement and analysis in various fields, including electromagnetics, life sciences, medical imaging, and materials engineering. To detect these magnetic fields with high resolution, magnetic field sensors utilizing nitrogen-vacancy centers (hereinafter referred to as "NV centers") in diamond are being actively researched. NV centers are defects existing within the diamond crystal, and NV center-based magnetic field sensors are quantum-based sensors capable of sensitively measuring external magnetic fields through optically detected magnetic resonance (ODMR) of electron spin states.

[0004] NV center-based magnetic field sensors have the advantage of providing higher spatial resolution compared to conventional magnetic field sensors such as MFM (Magnetic Force Microscopy) and SQUID (Superconducting Quantum Interference Device).

[0005] An NV center-based magnetic field detection device generally includes a sensor unit in which an NV center is formed on a diamond substrate, a laser light source for exciting the sensor, an optical detector for collecting a fluorescence signal, an electronic circuit and data processing device for analyzing the detected optical signal, and various optical components (lenses, mirrors, filters, etc.) for aligning and focusing the optical system.

[0006] However, existing NV-based magnetic field detection devices require a high-precision optical system and a complex optical alignment system, which has limitations such as increasing the overall size of the system, complex device configuration, and difficulty in maintenance.

[0007] In addition, there is a problem in that the spatial resolution is limited due to the use of bulk diamond, making it unsuitable for precise magnetic field measurements in localized regions at the nanometer level. Prior art literature

[0009] Published Patent Application No. 10-2021-0075402 (June 23, 2021) The problem to be solved

[0010] The present invention has been devised in consideration of the above points, and its technical objective is to provide a magnetic field detection device using a diamond nitrogen-void center capable of measuring magnetic fields with high spatial resolution at the nanometer level while enabling miniaturization and simplification of the device, and a method for manufacturing the same.

[0011] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0013] According to one embodiment of the present invention, a magnetic field detection device using a diamond nitrogen-void center is disclosed, comprising: an optical fiber; a diamond beam joined to the optical fiber and for transmitting laser light of the optical fiber; a cone member made of diamond material connected to the end of the diamond beam and having the shape of an inverted cone; and an optical signal emitting part formed of a diamond nitrogen-void center provided at the tip of the cone member and emitting an optical signal for magnetic field measurement as the laser light reaches.

[0014] In addition, the optical fiber may have a tapered shape such that its width gradually decreases along the length direction of the diamond beam.

[0015] In addition, the optical fiber and the diamond beam can be bonded to each other through a UV adhesive that is cured by ultraviolet rays.

[0016] In addition, the diamond beam can be connected to the upper part of the cone member.

[0017] In addition, a sample stage for moving a sample relative to the cone member for magnetic field detection may be additionally installed at the lower part of the cone member.

[0018] Additionally, the magnetic field detection device may further include an objective lens disposed on the upper side of the cone member and collecting the optical signal; and an optical signal detector that detects the optical signal passing through the objective lens.

[0019] Additionally, the magnetic field detection device may further include an optical filter installed between the objective lens and the optical signal detector, which separates and passes signals longer than a preset wavelength.

[0020] Meanwhile, according to another embodiment of the present invention, a method for manufacturing a magnetic field detection device using a diamond nitrogen-void center is disclosed, comprising the steps of: preparing a diamond substrate having a diamond nitrogen-void center layer formed therein; attaching a mask to the upper surface of the diamond substrate; forming the diamond beam and the cone member on the diamond substrate through bevel etching; joining the optical fiber to the diamond beam; and separating the optical signal emitting part from the diamond substrate.

[0021] In addition, the diamond nitrogen-vacuum center layer can be formed by the injection of nitrogen ions.

[0022] Additionally, the mask may include a first part corresponding to the planar shape of the cone member, a second part corresponding to the planar shape of the diamond, and a third part corresponding to the planar shape of the column part.

[0023] In addition, a pillar is formed on the opposite side of the cone member by bevel etching using the above mask, and the diamond beam can be cut from the pillar when the optical signal emitting part is separated.

[0024] In addition, the optical fiber can be bonded to the diamond beam through a UV adhesive that is cured by ultraviolet light. Effects of the invention

[0026] According to an embodiment of the present invention, the device can be miniaturized and simplified by using an optical fiber-based system, and by providing an optical signal emitting part at the tip of an inverted cone-shaped cone member, it is possible to measure a magnetic field with nanometer-level ultra-high resolution.

[0027] In addition, according to an embodiment of the present invention, it is possible to operate at room temperature and has the advantage of not affecting the sample when detecting a magnetic field due to its non-magnetic properties.

[0028] In addition, according to an embodiment of the present invention, there is an advantage of being able to improve process precision while lowering the process difficulty for a structure in which an NV center is formed at the tip of an inverted cone-shaped cone member by utilizing Faraday cage-based bevel etching. Brief explanation of the drawing

[0030] FIG. 1 is a perspective view of a magnetic field detection device using a diamond nitrogen-void center according to one embodiment of the present invention. FIG. 2 is an enlarged view of the cone member and diamond beam of FIG. 1. FIG. 3 is a diagram showing the operating state of a magnetic field detection device using a diamond nitrogen-void center according to one embodiment of the present invention. FIG. 4 is a flowchart illustrating a method for manufacturing a magnetic field detection device using a diamond nitrogen-void center according to an embodiment of the present invention. FIG. 5 is a diagram schematically illustrating the diamond nitrogen-void center layer, cone member, and diamond beam formation process of FIG. 4. Figure 6 is a diagram schematically illustrating the optical fiber junction and optical detector separation process of Figure 4. Specific details for implementing the invention

[0031] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0032] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0033] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0034] Hereinafter, embodiments of a magnetic field detection device using a diamond nitrogen-void center according to the present invention and a method for manufacturing the same will be described in detail with reference to the accompanying drawings. In describing with reference to the accompanying drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0035] FIG. 1 is a perspective view of a magnetic field detection device using a diamond nitrogen-void center according to one embodiment of the present invention, and FIG. 2 is an enlarged view of the cone member and diamond beam of FIG. 1.

[0036] As shown in FIGS. 1 and 2, a magnetic field detection device using a diamond nitrogen-void center according to the present embodiment includes an optical fiber (10), a diamond beam (20), a cone member (30), and an optical signal emitting part (40).

[0037] The optical fiber (10) is connected to a laser light source and functions to transmit laser light (3, see FIG. 3) from the laser light source. The optical fiber (10) may have a tapered shape so that its width gradually decreases along the direction of propagation of the laser light (3), that is, the length direction of the diamond beam (20).

[0038] The diamond beam (20) is bonded to the optical fiber (10) and configured to transmit the laser light (3) of the optical fiber (10) to the cone member (30). The optical fiber (10) and the diamond beam (20) may have a planar bonding surface so that they can be bonded to each other. The optical fiber (10) and the diamond beam (20) can be bonded to each other using a UV adhesive (15) that is cured by ultraviolet light. This allows for bonding with nanometer-scale precision in a simple manner, as well as maintaining a stable structure while minimizing optical loss when transmitting the laser light (3).

[0039] The cone member (30) is made of diamond material and has the shape of an inverted cone. The cone member (30) is connected to the end of the diamond beam (20). For example, the diamond beam (20) can be connected to the upper end of the cone member (30). For reference, the diamond beam (20) and the cone member (30) have a nano-scale size, and considering this, they may also be referred to as a diamond nano beam and a nano cone member (30).

[0040] The optical signal emitting unit (40) is provided at the tip of the cone member (30) and is formed as a diamond nitrogen-void center that emits an optical signal (5) for magnetic field measurement as laser light (3) arrives. The laser light (3) transmitted from the diamond beam (20) is transmitted to the optical signal emitting unit (40) at the tip through internal total reflection of the cone member (30), and the detection of the magnetic field is possible by measuring and analyzing the fluorescence intensity of the fluorescent light, which is the optical signal (5) emitted from the diamond nitrogen-void center through laser excitation of a specific wavelength (e.g., 532 nm).

[0041] A sample (1) for magnetic field detection is placed on the lower side of the cone member (30), and probes can be made over the entire area of ​​the sample (1) by relative movement between the cone member (30) and the sample (1). To this end, a sample stage may be installed on the lower side of the cone member (30) to move the sample (1) for magnetic field detection relative to the cone member (30). The sample stage can move the sample (1) in the direction of the arrow indicated in FIG. 1.

[0042] FIG. 3 is a diagram showing the operating state of a magnetic field detection device using a diamond nitrogen-void center according to one embodiment of the present invention.

[0043] Referring to FIG. 3, the magnetic field detection device may include an objective lens (50) that collects a light signal (5) emitted from a light signal emitting unit (40), and a light signal detector (52, or camera) that detects the light signal (5) that has passed through the objective lens (50).

[0044] An objective lens (50) may be positioned on the upper side of a cone member (30), and an optical filter (54) that separates and passes a signal of a wavelength greater than a preset wavelength (e.g., 600 nm) may be installed between the objective lens (50) and the optical signal detector (52). Additionally, it is also possible to install a mirror (56) between the objective lens (50) and the optical signal detector (52) to change the optical path of the optical signal (5).

[0045] To explain the operation of the magnetic field detection device using a diamond nitrogen-void center configured as described above, the laser light source emits laser light (3) of a specific wavelength, for example, 532 nm wavelength, to excite a point defect, which is transmitted as a laser beam through an optical fiber (10). The laser light (3) passes through the laser beam and cone member (30) to reach the optical signal emission part (40) formed as an NV center, and an optical signal (5) of 637 nm to 800 nm is emitted from the point defect.

[0046] The light signal (5) emitted from the light signal emission unit (40) passes through the objective lens (50), mirror (56), and light filter (54) and enters the light signal detector (52). The light signal detector (52) can detect the incident light signal (5) and convert it into a pulse signal. From this, the strength of the magnetic field can be measured by analyzing the fluorescence intensity of the light signal (5).

[0047] According to the magnetic field detection device configured as described above, a laser light (3) is transmitted to a diamond beam (20) through an optical fiber (10), and a magnetic field is measured through an optical signal emission part (40) located at the tip of a cone member (30), thereby allowing the magnetic field to be measured with high spatial resolution in a miniaturized structure.

[0048] In addition, the structure is such that an excitation laser of 532 nm wavelength is transmitted as a nano beam through an optical fiber, and a fluorescent signal of 637 to 800 nm wavelength generated from an optical signal emission unit (40) is collected through a cone member (30), thereby separating the transmission path of the laser light (3) and the collection path of the optical signal (5), so that magnetic field measurement with a high signal-to-noise ratio (SNR) is possible and signal loss can be minimized.

[0049] FIG. 4 is a flowchart illustrating a method for manufacturing a magnetic field detection device using a diamond nitrogen-void center according to an embodiment of the present invention. FIG. 5 is a diagram schematically illustrating the process of forming the diamond nitrogen-void center layer, cone member, and diamond beam of FIG. 4, and FIG. 6 is a diagram schematically illustrating the process of optical fiber bonding and optical detection part separation of FIG. 4.

[0050] To describe the method for manufacturing a magnetic field detection device using a diamond nitrogen-void center according to the present embodiment, first, a diamond base material (32) having a diamond nitrogen-void center layer (42) formed inside is prepared (S10). As shown in FIG. 5 (a), the diamond nitrogen-void center layer (42) can be formed by ion implanting nitrogen ions at a certain height inside the diamond base material (32). Meanwhile, in addition to this method, it is also possible to form the diamond nitrogen-void center layer (42) during diamond growth and then grow a diamond film of a certain thickness thereon.

[0051] Next, as shown in FIG. 5(b), a mask (60) is attached to the upper surface of the diamond base material (32) (S20). For reference, the upper side of FIG. 5(b) also shows a plan view to indicate the shape of the mask (60). Referring thereto, the mask (60) may have a configuration including a first part (61) corresponding to the planar shape of the cone member (30), a second part (62) corresponding to the planar shape of the diamond beam (20), and a third part (63) corresponding to the planar shape of the pillar part (70).

[0052] Next, a diamond beam (20) and a cone member (30) are formed on the diamond substrate (32) through bevel etching (S30). During this process, a pillar (70) can be formed on the opposite side of the cone member (30). Bevel etching can be performed using an ion etching method utilizing a Faraday cage. A Faraday cage is a metallic structure that blocks an internal electric field and is used to limit or modify the angle of incidence of ions. A Faraday cage is composed of a metal mesh with holes, through which ions are incident on the surface of the diamond substrate (32). The Faraday cage blocks the vertical incidence of ions and induces oblique incidence, thereby enabling the formation of the cone member (30) and the diamond beam (20).

[0053] Through such Faraday cage-based bevel etching, a structure is formed in which the cone member (30) and the column (70) are connected through both ends of the diamond beam (20), as shown in Fig. 5 (c). Here, the column (70) functions to support the diamond beam (20) together with the cone member (30) so that the diamond beam (20) can be supported at a certain height away from the diamond base material (32).

[0054] Next, as shown in (a) of FIG. 6, the mask (60) is removed from the upper surface of the cone member (30) and the diamond beam (20), and as shown in (b), the optical fiber (10) is bonded to the diamond beam (20) (S40). The bonding of the optical fiber (10) can be performed using a UV adhesive (15) as described above, and the optical fiber (10) can be bonded to the diamond beam (20) by applying the UV adhesive (15) and then irradiating ultraviolet rays to cure the UV adhesive (15) while the optical fiber (10) is temporarily bonded to the diamond beam (20).

[0055] Next, as shown in FIG. 6(b), the optical signal emitting part (40) is separated (S59) from the diamond base material (32) to complete the manufacture of the magnetic field detection device. At this time, the magnetic field detection device can be separated from the base material by cutting the diamond beam (20) from the pillar (70).

[0056] According to the above method, it is possible to precisely manufacture the shape of an inverted cone at the nanoscale level and to manufacture it by accurately positioning the NV center at the tip of the cone member.

[0057] Although the present invention has been described above with reference to specific embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0059] 1: Sample 3: Laser light 5: Optical signal 10: Optical fiber 15: UV adhesive 20: Diamond beam 30: Cone component 32: Diamond base material 40: Optical signal emitter 42: Diamond nitrogen-void center layer 50: Objective lens 52: Optical signal detector 54: Light filter 56: Mirror 60: Mask 70: Pillar

Claims

Claim 1 A magnetic field detection device using a diamond nitrogen-void center, comprising: an optical fiber for transmitting laser light emitted from a laser light source; a diamond beam joined to the optical fiber and transmitting the laser light of the optical fiber; a cone member made of diamond material having an inverted cone shape, with an upper end connected to the end of the diamond beam; an optical signal emitting part formed of a diamond nitrogen-void center provided at the tip of the cone member and emitting an optical signal for magnetic field measurement as the laser light reaches; and a sample stage installed at the bottom of the cone member and for moving a sample for magnetic field detection relative to the cone member. Claim 2 A magnetic field detection device using a diamond nitrogen-void center according to claim 1, characterized in that the optical fiber has a tapered shape such that its width gradually decreases along the longitudinal direction of the diamond beam. Claim 3 A magnetic field detection device using a diamond nitrogen-void center, characterized in that, in claim 1, the optical fiber and the diamond beam are bonded to each other through a UV adhesive that is cured by ultraviolet rays. Claim 4 delete Claim 5 delete Claim 6 A magnetic field detection device using a diamond nitrogen-void center, characterized in that, in claim 1, it further comprises: an objective lens disposed on the upper side of the cone member and collecting the optical signal; and an optical signal detector that detects the optical signal passing through the objective lens. Claim 7 A magnetic field detection device using a diamond nitrogen-void center, characterized in that, in claim 6, it further comprises an optical filter installed between the objective lens and the optical signal detector, which separates and passes signals longer than a preset wavelength. Claim 8 A method for manufacturing a magnetic field detection device using a diamond nitrogen-void center according to claim 1, comprising: preparing a diamond base material having a diamond nitrogen-void center layer formed therein; attaching a mask to the upper surface of the diamond base material; forming the diamond beam and the cone member on the diamond base material through bevel etching; joining the optical fiber to the diamond beam; and separating the optical signal emitting part from the diamond base material. Claim 9 A method for manufacturing a magnetic field detection device according to claim 8, wherein the diamond nitrogen-void center layer is formed by the injection of nitrogen ions. Claim 10 A method for manufacturing a magnetic field detection device according to claim 8, wherein the mask comprises a first part corresponding to the planar shape of the cone member, a second part corresponding to the planar shape of the diamond, and a third part corresponding to the planar shape of the pillar part. Claim 11 A method for manufacturing a magnetic field detection device according to claim 8, wherein a pillar is formed on the opposite side of the cone member by bevel etching using the mask, and the diamond beam is cut from the pillar when the optical signal emitting part is separated. Claim 12 A method for manufacturing a magnetic field detection device according to claim 8, wherein the optical fiber is bonded to the diamond beam through a UV adhesive that is cured by ultraviolet rays.

Images