Inventive name: Atomic trapping device, atomic cooling device, light splitting device, optical lattice clock, quantum computer, coil, atomic trapping method, atomic cooling method, and light splitting method

Abstract

An atom trapping device 10 for trapping atoms has an atom trapping section 16 into which an atomic gas beam is incident. The atom trapping section 16 has a plurality of optical elements forming a laser beam group 18 and a magnetic field generating section 22. The magnetic field generating section 22 has at least two spiral coils and, as necessary, a tapered solenoid coil that optimizes the magnetic field in the direction of guidance. The spiral coils are configured so that the front end becomes thin and the winding density becomes sparse as the direction in which atoms are guided is advanced. The spiral coils are relatively arranged so that the distance between them decreases as the direction in which atoms are guided is advanced. The tapered solenoid coil generates a magnetic field so that the guidance of atoms and laser cooling in the guidance are optimized by adjusting the component in the direction in which atoms are guided in the magnetic field generated by the spiral coils. The atom trapping section 16 can also have a baseball coil instead of the spiral coils and the tapered solenoid coil.

Description

Technical Field

[0001] This invention relates to atomic trapping devices, atomic cooling devices, spectrophotometers, optical lattice clocks, quantum computers, coils, atomic trapping methods, atomic cooling methods, and spectrophotometer methods. Background Technology

[0002] As a method for trapping atoms in space, magneto-optical traps (hereinafter also referred to as "MOTs") are known (see, for example, non-patent documents 1 and 2). The principle of MOTs is outlined below.

[0003] Motion-Trap (MTT) achieves the cooling and trapping of atoms by utilizing the frictional force of laser cooling and the restoring force generated by the Zeeman effect induced by a quadrupole magnetic field. In MOT, a quadrupole magnetic field is generated using an anti-Helmholtz coil (two coils with current flowing in opposite directions). Pairs of opposing laser beams are irradiated onto this anti-Helmholtz coil from three mutually orthogonal directions, with the area near the intersection of the laser beams becoming the center. The strength of this quadrupole magnetic field is 0 at the center of the anti-Helmholtz coil and increases with distance from the center. Due to this quadrupole magnetic field, the resonant frequency of the atom undergoes a significant Zeeman shift with distance from the center. At this point, by appropriately selecting the polarization of the laser beam, a restoring force is generated with radiation pressure towards the origin. Thus, laser-cooled atoms can be trapped. The region where atoms are trapped by this method is called the MOT region.

[0004] Another background technology of this invention is the optical lattice clock. The optical lattice clock is an atomic clock proposed by the inventors in 2001. High-precision atomic clocks not only support the development of science and technology through precise measurements, but also play a vital role as a fundamental system supporting modern society, such as navigation systems carried by satellites or the construction of high-capacity, high-speed communication networks. Since the transition frequency of the microwave transition of cesium atoms was defined as a "second" in 1967, cesium atomic clocks have been used as a time / frequency standard for half a century. During this period, through the introduction of laser cooling technology or the development of atomic fountain clocks, the accuracy of cesium atomic clocks has improved by one decimal place every decade, currently achieving an uncertainty of approximately 15 decimal places and being shared globally as International Atomic Time.

[0005] On the other hand, with the rapid development of optical frequency control technologies, such as optical frequency combs, narrow-linewidth laser sources, and fiber optic frequency transmission, recent research on atomic clocks is gradually shifting towards the development of optical clocks based on atomic transitions in the optical frequency region. The accuracy of a clock is directly proportional to the frequency used as a reference. Therefore, optical clocks based on optical frequencies can achieve accuracy several orders of magnitude higher than cesium clocks based on microwaves.

[0006] In 2001, the inventors proposed an optical lattice clock that achieves high-precision atomic clocking in a short time by using the resonant frequency of the optical region containing millions of atoms trapped within an optical lattice generated by a laser beam as a reference. The optical lattice clock is positioned as the next generation of atomic clocks, capable of achieving 18-bit precision, far exceeding the accuracy of cesium clocks, in a short average time of just a few seconds.

[0007] Typically, the principle of an optical atomic clock is to illuminate atoms with a laser beam and control the frequency of the laser beam to ensure it always resonates with the resonant transitions of the atoms, which serve as the clock reference, thereby achieving the inherent and unchanging frequency or time of the atoms. On the other hand, to achieve an accurate clock, it is necessary to eliminate perturbations around the atoms and accurately read their frequencies. Particularly important is eliminating the frequency shift caused by the Doppler effect resulting from the thermal motion of the atoms.

[0008] As a type of optical atomic clock, the optical lattice clock utilizes an optical trap formed by laser beam interference to confine atoms within a region narrower than the wavelength of light, thereby eliminating the Doppler effect associated with atomic motion. On the other hand, if atoms are confined with a laser beam, the resonant frequency of the atoms will shift due to the laser beam. This effect can be reduced by selecting a specific wavelength known as the "magic wavelength," thus eliminating the influence of the optical lattice itself. In fact, the magic wavelengths of strontium, ytterbium, mercury, cadmium, magnesium, and other elements have been experimentally determined.

[0009] To evaluate the accuracy of the realized clock and align the frequency of the optical lattice clock with International Atomic Time, the absolute frequency of the resonant transition of strontium atoms was determined. Subsequently, research institutions in the United States and France conducted additional experiments, confirming the repeatability of the determination. In 2006, the optical lattice clock using strontium atoms was adopted as a "secondary representation of the second," considered a strong candidate for redefining the "second." As the accuracy of optical lattice clocks improves, the uncertainty of cesium clocks gradually begins to limit measurement accuracy. Therefore, to conduct evaluations with higher precision, developing multiple optical lattice clocks and directly comparing them has become an indispensable step.

[0010] For example, patent documents 1-3 disclose the latest technology for optical lattice clocks. Patent document 1 describes a "moving optical lattice" that traps atoms near lattice points and transports them by moving them along an atomic movement path. Patent document 2 describes a method for setting an effective magic frequency. Patent document 3 describes a radiation shield that reduces the effects of blackbody radiation emitted from surrounding walls.

[0011] The next step in the application of optical lattice clocks is to explore new applications for high-precision clocks and realize their practical application. If clock measurements can be performed with an accuracy of up to 18 bits, then, for example, based on the general relativistic effects caused by gravity, even a difference of only 1 cm in height on the ground can be detected as a difference in the rate of time passage. If this relativistic effect is utilized, high-precision clocks can serve as high-precision gravitational potential meters, becoming precise measuring tools for probing new worlds. As an example, if optical lattice clocks can be made portable and used in the field, their application potential in new geodetic techniques such as altitude measurement between distant locations or observation of crustal movements can be expanded. Furthermore, by mass-producing and deploying highly reliable small clocks in various locations to continuously monitor the temporal changes of gravitational potential, it is conceivable that they can be applied to the detection of crustal movements and spatial mapping of gravitational fields. In the future, as clocks become smaller and more portable, they are expected to contribute to society as a new foundational technology.

[0012] Existing technical documents Patent documents Patent Document 1: International Publication No. 2014 / 027637 Patent Document 2: Japanese Patent Publication No. 2018-510494 Patent Document 3: Japanese Patent Application Publication No. 2019-129166 Non-patent literature Non-patent literature 1: ELRaab et al, M Prentiss, A Cable, S Chu, DE Pritchard, "Trapping of Neutral Sodium Atoms with Radiation Pressure", Physical. Review. Letters. 59, 2631 (1987). Non-patent literature 2: T. Bergeman, G. Erez, and HJ Metcalf, “Magnetostatictrapping fields for neutral atoms”, Physical Review A 35, 1535 (1987). Non-patent literature 3: Hidetoshi Katori, “Longitudinal Ramsey spectroscopy of atoms for continuous operation of optical clocks”, Applied Physics Express 14, 072006 (2021). Non-patent document 4: Ryoto Takeuchi, Hayaki Chiba, Shoichi Okaba, MasaoTakamoto, Shigenori Tsuji, and Hidetoshi Katori, “Continuous outcoupling of ultracold strontium atoms combining three different traps”, Applied PhysicsExpress 16, 042003 (2023) Non-Patent Literature 5: Masami Yasuda and Hidetoshi Katori, “Lifetime Measurement of the 3P2 Metastable State of Strontium Atoms”, Phys. Rev. Lett. 92, 153004 - Published 15 April 2004 Non-Patent Literature 6: SB Nagel, CE Simen, S. Laha, P. Gupta, VSAshoka, and TC Killian, “Magnetic trapping of metastable 3P2 atomicstrontium”, PHYSICAL REVIEW A 67, 011401, 2003. Non-patent document 7: Tomoya Akatsuka, Koji Hashiguchi, Tadahiro Takahashi, Noriaki Ohmae, Masao Takamoto and Hidetoshi Katori, “Three-stage lasercooling of Sr atoms using the 5s5p3P2 metastable state below Dopplertemperatures”, PHYSICAL REVIEW A 103, 023331 (2001). Non-patent document 8: S. Wu, RC Brown, WD Phillips, and JV Porto, "Pulsed Sisyphus scheme for laser cooling of atomic (anti)hydrogen", PhysicalReview Letters 106, 213001 (2011). Summary of the Invention The problem that the invention aims to solve In devices such as atomic clocks or atomic interferometers, it is desirable to continuously supply cooled atomic gas in order to perform measurements continuously. However, if the atomic gas is kept in the same position, different operations cannot be performed on it. As a result, it is difficult to continuously supply atomic gas to subsequent devices.

[0013] To address this issue, one approach is to create a quasi-three-dimensional quadrupole magnetic field with a magnetic field distribution where the magnetic field gradient in one axis is weaker than those in the other two axes (see, for example, Non-Patent Document 4). The quasi-three-dimensional quadrupole magnetic field described here refers to a magnetic field that combines the features of a spherical quadrupole trap required for MOT (Metastatic Oriented Tunneling) with a linear quadrupole guide with a bias magnetic field. This linear quadrupole guide guides and moves atoms that have been moderated to a magnetically trappable state. Thus, atoms that have been laser-cooled and moderated to a metastable state in the MOT region can be magnetically guided and magnetically trapped to their final trapping position.

[0014] As one method for compactly generating such a quasi-three-dimensional quadrupole magnetic field, consider using a rod-shaped permanent magnet (hereinafter referred to as a magnetic rod).

[0015] However, when generating a quasi-three-dimensional quadrupole magnetic field using a magnetic rod, the large leakage magnetic field from the rod becomes a problem. For example, when attempting to split the beam at a distance of approximately 2 cm from the magnetic rod, the leakage magnetic field in the splitting region reaches tens of G. Such a strong leakage magnetic field will adversely affect the beam splitting and is therefore not preferred. Therefore, reducing the leakage magnetic field becomes a key challenge when generating a quasi-three-dimensional quadrupole magnetic field.

[0016] Below, refer to Figure 1 The magnetic field gradient generated by the anti-Helmholtz coil is explained. Figure 1 This is a schematic diagram of an anti-Helmholtz coil with radius R and center distance 1.25R. The direction of the straight line passing through the centers of the two coils is defined as the x-axis. Assume that currents I (A) flow in opposite directions through the two coils. The magnetic field gradient generated by these coils in the x-axis direction is represented by Equation 1 below.

[0017] [Formula 1]

[0018] For example, if I=100A and R=1cm, then the magnetic field gradient is 100G / cm.

[0019] exist At time R, the distribution pattern of the residual magnetic field B is as follows: Therefore, miniaturizing the system's structure helps reduce the residual magnetic field.

[0020] On the other hand, if the typical size of the coil is set to D, the current required to generate the same magnetic field gradient is 1 / D. 2 Therefore, the power loss is 1 / D. 4 Therefore, miniaturizing the system structure also helps to reduce power consumption.

[0021] However, to realize a magneto-optical trap (MOT), laser cooling of atoms requires approximately D = 2 cm. Therefore, a method is needed to continuously connect the large-volume MOT magnetic field with a compact magnetic field trap.

[0022] The purpose of this invention is to generate a compact quasi-three-dimensional quadrupole magnetic field to realize MOT and its subsequent magnetic trap, and to minimize the resulting leakage magnetic field.

[0023] Methods for solving problems To address the aforementioned issues, one aspect of the present invention provides an atomic trapping device for trapping atoms, wherein the atomic trapping device includes an atomic trapping section for receiving an atomic gas beam. The atomic trapping section includes a plurality of optical elements and a magnetic field generating section, the plurality of optical elements forming a laser beam assembly. The magnetic field generating section includes at least two helical coils and a conical solenoid coil. The helical coils are configured such that their leading ends taper and their winding density decreases as they travel in the direction in which the atoms are guided; the helical coils are arranged opposite each other such that their spacing decreases as they travel in the direction in which the atoms are guided; and the conical solenoid coil generates a magnetic field to counteract the component of the magnetic field generated by the helical coils in the direction in which the atoms are guided.

[0024] In one embodiment, the magnetic field generating unit may form a magnetic field distribution as follows: generating a first region with a large magnetic field gradient for realizing a magneto-optical trap, and a second region with a small magnetic field gradient in the guiding direction for realizing magnetic field guidance of atoms.

[0025] In one embodiment, the magnetic field distribution may also be a quasi-three-dimensional quadrupole magnetic field, wherein the quasi-three-dimensional quadrupole magnetic field is a spherical quadrupole magnetic field in the first region and a linear quadrupole magnetic field with a bias magnetic field in the second region.

[0026] In one embodiment, the atom trapping device may also include a magnetic field trap that traps the guided atoms into a final trapping region.

[0027] In one embodiment, the volume of the first region may be 1000 mm. 3 The final captured area volume is 1mm. 3 the following.

[0028] In one embodiment, the strength of the leakage magnetic field from the magnetic field generating part may be less than 1G at a position of more than 2cm from the magnetic field generating part.

[0029] In one embodiment, the atoms may be guided in the direction of gravity.

[0030] In one embodiment, the spiral coil and the tapered solenoid may also be made of a multilayer PCB substrate.

[0031] In one embodiment, the magnetic field generating part may include a baseball coil.

[0032] In one embodiment, the atom may be a strontium atom.

[0033] In one embodiment, the atom may be a ytterbium atom.

[0034] Another aspect of the present invention is an atomic cooling device. This device includes the atomic trapping device described above and a Doppler cooling mechanism.

[0035] Another aspect of the present invention is a spectrophotometer. This apparatus includes the atomic cooling device and the spectrophotometer described above.

[0036] Another aspect of the present invention is an optical lattice clock. This optical lattice clock includes a physical package, an optical system assembly, a control unit, and a PC. The physical package includes the atomic cooling device described above, and a clock transition excitation unit.

[0037] Another aspect of the present invention is a quantum computer. This quantum computer includes a physical package, an optical system, a control unit, and a PC. The physical package includes the atomic cooling device described above, and a clock transition excitation unit corresponding to the operation of the qubits.

[0038] Another aspect of the invention is a coil. This coil is configured as a spiral coil that tapers at the front end and becomes less densely wound as it moves forward.

[0039] Another aspect of the present invention is an atomic trapping method. This method is a method for trapping atoms using an atomic trapping device equipped with an atomic trapping section, comprising: a step of supplying atoms; a step of magneto-optical trapping of the atoms using the atomic trapping section; and a step of magnetically trapping and guiding the atoms using the atomic trapping section. The atomic trapping section includes a plurality of optical elements and a magnetic field generating section, the plurality of optical elements forming a laser beam. The magnetic field generating section includes at least two helical coils and a conical solenoid coil. The helical coils are configured such that their leading ends become thinner and their winding density becomes looser as they travel in the direction in which the atoms are guided. The helical coils are arranged opposite each other such that the distance between them decreases as they travel in the direction in which the atoms are guided. The conical solenoid coil generates a magnetic field to counteract the component of the magnetic field generated by the helical coils in the direction in which the atoms are guided.

[0040] In one embodiment, the magnetic field generating part may have a baseball coil instead of a spiral coil and a conical solenoid coil.

[0041] Another aspect of the present invention is an atomic cooling method. This method involves cooling atoms using an atomic cooling device equipped with an atomic cooling apparatus and a Doppler cooling mechanism, comprising: a step of supplying atoms; a step of magneto-optical trapping of atoms using an atomic trapping unit; a step of magnetically trapping and guiding atoms using the atomic trapping unit; and a step of Doppler cooling of the guided atoms using the Doppler cooling mechanism.

[0042] Another aspect of the present invention is a spectral dispersion method. This method involves using a spectral dispersion apparatus equipped with an atomic cooling device and a spectral dispersion section to perform spectral dispersion, comprising: a step of supplying atoms; a step of magneto-optical capturing of the atoms using an atomic capturing unit; a step of magnetically capturing and guiding the atoms using the atomic capturing unit; a step of Doppler cooling of the guided atoms using a Doppler cooling mechanism; and a step of performing spectral dispersion using the spectral dispersion section.

[0043] In one embodiment, the atomic cooling device may also include a Sisyphus cooling mechanism instead of a Doppler cooling mechanism, including the step of using the Sisyphus cooling mechanism to perform Sisyphus cooling on the guided atoms.

[0044] Invention Effects According to the present invention, a compact quasi-three-dimensional quadrupole magnetic field for achieving MOT and subsequent magnetic traps can be generated while minimizing the leakage magnetic field generated. Attached Figure Description

[0045] [ Figure 1 [ ] is a schematic diagram of an inverse Helmholtz coil.

[0046] [ Figure 2 [ ] is a diagram representing the energy levels of a strontium atom.

[0047] [ Figure 3 [] is a diagram showing the operation flow of the atomic trapping method in the implementation method.

[0048] [ Figure 4 The diagram shows a configuration with two coils tapering towards the front end in the direction the atom is being guided.

[0049] [ Figure 5 [Illustration of a coil] is a schematic diagram of a coil whose winding density becomes less dense as it moves toward the front end.

[0050] [ Figure 6 [ ] is a schematic diagram of a tapered solenoid coil.

[0051] [ Figure 7 [Illustration 1] is a perspective view of the atom trapping device according to the first embodiment.

[0052] [ Figure 8 [Illustration 1] is a perspective view of the atom trapping device according to the first embodiment.

[0053] [ Figure 9 [Image showing the atom trapping device of the first embodiment viewed from the -z direction]

[0054] [ Figure 10 [Image showing the atomic trapping device of the first embodiment viewed from the y-direction]

[0055] [ Figure 11 ] Figure 11 (a) is a plan view of the magnetic field generating part as seen from the +z direction. Figure 11 (b) is a graph showing the absolute value of the magnetic field strength on the y-axis and the resultant force of the magnetic force and gravity acting on the atoms.

[0056] [ Figure 12 ] indicates by Figure 11 (a) A contour plot of the leakage magnetic field generated by the system. Figure 12 (a) is the yz plane at x=0. Figure 12 (b) is the xy plane at z=0.

[0057] [ Figure 13 [ ] is a schematic diagram of an embodiment of the magnetic field generating unit.

[0058] [ Figure 14 This is a schematic diagram of a magnetic field generating unit composed of four multilayer PCB substrates.

[0059] [ Figure 15 [] is a diagram showing a coil with wiring on the first layer of a multilayer PCB substrate.

[0060] [ Figure 16 [ ] is a schematic diagram of a modified example of the magnetic field generating unit.

[0061] [ Figure 17 [ ] is a functional block diagram of the optical lattice clock in the fourth embodiment.

[0062] [ Figure 18 [Illustrative diagram] is a schematic representation of the third embodiment.

[0063] [ Figure 19 [Illustrative diagram] is a schematic representation of the fourth embodiment. Detailed Implementation

[0064] The present invention will now be described based on preferred embodiments and with reference to the accompanying drawings. These embodiments are merely illustrative and not intended to limit the technical features of the invention. Not all features or combinations thereof described in the embodiments are necessarily essential technical features of the invention. For identical or equivalent constituent elements, components, and processes shown in the various drawings, repeated descriptions are appropriately omitted. Furthermore, the proportions and shapes of the parts shown in the figures are provided for ease of explanation and should not be interpreted restrictively unless otherwise stated. Additionally, when terms such as "first" and "second" are used in this specification or claims, unless otherwise stated, these terms do not indicate any order or importance, but are only used to distinguish one structure from others. Furthermore, in the various drawings, parts that are not important to the description of the embodiments are omitted.

[0065] [First Implementation Method] The atomic trapping apparatus will now be described in detail as a first embodiment of this disclosure. First, the operational flow of the atomic trapping apparatus related to this embodiment will be explained. The operations performed sequentially generally include a first step and a second step. In the first step, atomic gas is generated from solid atoms. In the second step, the generated atomic gas is trapped in the MOT region, and then the atoms are magnetically trapped and guided to the final trapping position.

[0066] For example, external forces used to guide neutral atoms belonging to alkaline earth metals include: gravity (an effective external force when the mass of the atom is finite), magnetism (an effective external force when the magnetic moment of the atom is finite), laser radiation pressure (e.g., laser radiation pressure used for laser deceleration, magneto-optical traps (MOTs), or optical clumps), and optical dipole force (used for optical dipole traps, optical lattices, etc.). Gravity and magnetism will be explained here.

[0067] Alkaline earth metal atoms with two electrons in their outermost shell have a ground state of spin singlet, with both angular momentum and total orbital angular momentum being zero. In this case, it seems difficult to use magnetism as an external force to propel the atomic gas. However, it is known that by optical pumping generated during laser cooling, atoms in the ground state can be generated... 3 Atoms in the P2 state. The following explanation uses strontium atoms as an example, but this method can also be applied to atoms belonging to Group 2 or Group 2b of the periodic table, such as magnesium or calcium atoms, or ytterbium atoms.

[0068] Figure 2 This represents the energy levels of a strontium atom. Based on existing research using strontium atoms, it is known that the energy levels at these levels are... 3 Atoms in the P2 state have a lifetime of over 100 seconds (see, for example, Non-Patent Document 5). Furthermore, according to another study using strontium atoms, it is known that atoms can be trapped magnetically (see, for example, Non-Patent Document 6). Therefore, it is possible to achieve a long lifetime and be considered metastable. 3 Atoms in the P2 state move under the influence of gravity.

[0069] Figure 3 This describes the operational flow of the atomic trapping method related to the implementation method. In the implementation method, the following steps S1 to S3 are performed.

[0070] S1: Supplying low-speed atoms S2: Magneto-optical trapping (MOT) using a quasi-three-dimensional quadrupole magnetic field. S3: Magneto-optical guidance using a quasi-three-dimensional quadrupole magnetic field [The principle of atomic trapping] Below, we will use strontium atoms ( 88The principle of atom trapping in the implementation method will be explained using Sr as an example. Here, a three-dimensional coordinate system {x, y, z} is defined. The x-axis, y-axis, and z-axis are mutually orthogonal axes. For other even-numbered isotopes (e.g., Sr), 86 Sr) or odd-numbered isotopes with nuclear spin ( 87 The same operation can be achieved in Sr).

[0071] The quasi-three-dimensional quadrupole magnetic field shown in steps S2 to S3 has a magnetic field distribution in which one axial magnetic field gradient is weaker than the other two axial magnetic field gradients.

[0072] The quasi-three-dimensional quadrupole magnetic field has a region containing the magnetic field distribution represented by Equation 2 below (the linear quadrupole guide in the middle of the quasi-three-dimensional quadrupole magnetic field).

[0073] [Equation 2]

[0074]

[0075] {G x G y G z} represents the magnetic field gradient around the zero magnetic field location. In the example above, the magnetic field gradient along the y-axis is smaller than the magnetic field gradients along the x and z axes, and the magnetic force along the y-axis ( It is weaker than the magnetic force in the x and z axes.

[0076] In step S2, due to the aforementioned quasi-three-dimensional quadrupole magnetic field and in 1 S0- 1 The interaction of the 461nm laser beam resonating between the P1 states causes atoms to experience restorative forces, trapping them near the zero magnetic field position (i.e., the origin). Furthermore, during the aforementioned laser cooling process, through the interaction of the laser beam with the atoms in the P1 state resonant state... 1 P1 state is 1 The D2 condition has eased to 3 The optical pumping process in the P2 state generates a metastable state. 3 Atoms in the P2 state.

[0077] In step S3, 3 In an atom in the P2 state, the magnetic quantum number m j Atoms with a magnetic potential of 1 or 2 are energy-stable in a weak magnetic field and are magnetically trapped near the zero magnetic field position of a quasi-three-dimensional quadrupole magnetic field. Near the zero magnetic field position, the magnetic interaction potential energy U between the atom and the quasi-three-dimensional quadrupole magnetic field is... mag It is represented by the following formula (1).

[0078] [Formula 3] …(1) g is the g factor (in the state of the atom, g is...).3 In state P2, g=3 / 2), μ B It is the Bohr magneton.

[0079] In addition, the magnetic force F acting on the atom mag It is represented by the following formula (2).

[0080] [Formula 4] …(2) Gravity (F=mg) acts on the atom along the y-direction. The magnetic force F at a position where gravity is greater than zero magnetic field... mag When the y-component is zero, the atom will move from the zero magnetic field position along the y-direction (i.e., the direction of gravity) due to gravity. The atom is trapped in the final trapping position within the final trapping region by a magnetic field trap. Preferably, the volume of the MOT region (magneto-optical trap region) is 1000 mm². 3 The final captured area volume is 1mm. 3 the following.

[0081] The atoms used as the sample are at magnetic quantum number m. j =2 88 In the case of Sr atoms, the gravitational coefficient is taken as 9.8 m / s². 2 The magnetic force that balances gravity can be achieved through a magnetic field gradient of 5.2 G / cm. That is, along the y-axis, in order for atoms to move from the zero magnetic field center under the influence of gravity, the magnetic field gradient from the zero magnetic field center to the trapped position needs to be less than 5.2 G / cm. On the other hand, in order to use a magneto-optical trap... 1 The atoms in the S0 state are cooled and trapped for several milliseconds or more, allowing them to cool down to... 3 In the P2 state, atoms are magnetically trapped, preferably using a magnetic field gradient of 30~100 G / cm (the spherical quadrupole trap regions at both ends of the quasi-three-dimensional quadrupole magnetic field). A quasi-three-dimensional quadrupole magnetic field with strong anisotropy can satisfy these conditions.

[0082] Next, the generation of a strongly anisotropic quasi-three-dimensional quadrupole magnetic field used to perform steps S1 to S3 will be explained. As mentioned above, when generating a quasi-three-dimensional quadrupole magnetic field using a magnetic rod, there is a problem of a large leakage magnetic field from the magnetic rod. Assuming the deceleration distance D of the atoms is set to D~10mm, the MOT region needs to have a magnetic field of D. 3 ~1000mm 3 The volume of the quadrupole magnetic field used to realize the MOT is approximately d^2. Therefore, the quadrupole magnetic field used to realize the magnetic trap also needs to have a similar volume. On the other hand, after the atoms are cooled by laser, the length d of the magnetically trapped region is approximately d^2 ~ 1 mm. Therefore, the volume of the quadrupole magnetic field used to realize the magnetic trap is d^2. 3 ~1mm 3 .

[0083] The leakage region of a quadrupole magnetic field is approximately the distance between the coils. Therefore, by reducing the area of ​​the magnetic trap, the range of the leakage magnetic field can be reduced. To achieve this, as... Figure 4 As shown, two coils 221A and 221B (e.g., trapezoidal coils) are formed, with the leading ends of both coils 221A and 221B tapering as they travel in the direction the atoms are guided (y-axis direction). Coils 221A and 221B have approximately the same shape and size. Consider arranging coils 221A and 221B opposite each other such that the distance between them decreases as they travel in the y-axis direction, and consider this as an anti-Helmholtz coil. That is, if a reverse current is passed through coils 221A and 221B arranged in this way, a quadrupole magnetic field will be generated. (Refer to...) Figure 11 The final capture position is formed at the front end (y=70mm) of coils 221A and 221B, extending approximately 3mm (y=70mm) into the coil. MT At a location (=67mm). Set this y-coordinate as y... MT Additionally, starting from the rear end (y=0mm) of coils 221A and 221B, extend approximately 20mm inwards into the coil (set this y coordinate as y). MOT Centered on ), a MOT region (y) is formed. MOT =20mm). By selecting the shape and size of coils 221A and 221B, it is possible to achieve the desired result at y=y. MT The volume of the region formed nearby is d 3 ~1mm 3 In y=y MOT The volume of the nearby region is D 3 ~1000mm 3 This is expected to enable the formation of appropriately sized MOT regions and magnetic trap regions.

[0084] However, in the above structure, if a uniform current is supplied to coils 221A and 221B, there is a problem that the magnetic field gradient of the guide section will increase unnecessarily.

[0085] To solve this problem, such as Figure 5 As shown, the coil 222, whose tip tapers towards the y-axis, is configured such that its winding density decreases towards the y-axis. That is, the coil 222 has a helical shape. Figure 5 In the example, coil 222 consists of four turns: a, b, c, and d. Two such coils, 222A and 222B, are respectively... Figure 4 It is configured like the 221A and 221B. By appropriately selecting the coil winding density, it is possible to reduce the volume of the magnetic guide and trapping area while maintaining a constant magnetic field gradient.

[0086] If Figure 5 Spiral coils, such as Figure 4 The advantage of this configuration and the application of current is that it keeps the magnetic field gradient in the plane perpendicular to the y-axis constant. However, it also creates y-axis confinement, which hinders atomic motion and negatively impacts subsequent measurements.

[0087] To solve this problem, such as Figure 6 As shown, a conical solenoid coil 223 is provided. This can counteract the confinement in the y-axis direction caused by the helical coils 223A and 223B, and avoid hindering the movement of atoms.

[0088] [Specific Structure of the Implementation Method] Below, refer to Figures 7-10 The atomic trapping apparatus and atomic trapping method related to the implementation method are described. Figure 7 This is a perspective view of the atom trapping device 10 related to the implementation method. Figure 8 This is a three-dimensional view of the atom trapping device 10. Figure 9 This is a diagram showing the atom trapping device 10 viewed from the -z direction. Figure 10 This is a diagram showing the atomic trapping device 10 as viewed from the y-direction. A three-dimensional coordinate system {x, y, z} is defined. The x-axis, y-axis, and z-axis are mutually orthogonal. The x-direction is the direction of the atomic beam emitted from the reactor. The y-direction is the direction of gravity.

[0089] The atomic trapping device 10 associated with the implementation includes an atomic furnace 12, a Zeeman reducer 14, and an atomic trapping unit 16. The atomic furnace 12, Zeeman reducer 14, and atomic trapping device 10 are installed in an ultra-high vacuum environment. In the figures, illustrations of the fixtures of each module, the observation windows of the input / output laser beams, the vacuum exhaust ports, and the vacuum exhaust pumps are omitted.

[0090] The atomic furnace 12 includes a sample container, a heater, a capillary nozzle, a thermometer, an electrical connector, and a heat radiation shield. A sample is placed inside the sample container. For example, strontium atoms (…) are used. 87 Sr or 88 Sr) is used as the sample. The sample in the sample container is heated using a heater, causing atoms to evaporate and generate atomic gas. A capillary nozzle is connected to the sample container. The atomic gas is ejected through the capillary nozzle in the form of a directional atomic beam. A thermometer is used to measure the temperature of the sample container. An electrical connector is used to supply power to the heater. A heat radiation shield is used to shield the heater and sample container from outward heat radiation. A known atomic furnace can be used as the atomic furnace 12. The atomic beam emitted from the atomic furnace 12 travels to the subsequent Zeeman reducer 14.

[0091] The Zeeman reducer 14 includes a central through-hole and a magnetic field generating section, which is disposed around the central through-hole and extends in the x-direction. The magnetic field generating section includes, for example, a solenoid coil, generating a magnetic field along the central axis (x-axis) of the central through-hole, which extends in the x-direction. As an example, the magnetic field generating section generates a magnetic field whose intensity decreases with distance from the furnace 12. Additionally, a resonant laser beam 14b irradiates the central through-hole in a direction opposite to the direction of travel of the atomic beam (-x direction). The atomic beam emitted from the furnace 12 is irradiated into the central through-hole and travels in the x-direction within it. The Zeeman reducer 14, utilizing the resonant laser beam 14b and the gradient magnetic field formed by the magnetic field generating section, reduces the velocity of the atomic beam emitted from the furnace 12 with a high initial velocity to a velocity that can be captured by the subsequent atomic trapping device 10, according to the Zeeman reduction method. The high-temperature atomic beam travels towards the atomic trapping device 10 within the central through-hole while being reduced according to the Zeeman reduction method. As a Zeeman reducer 14, a known Zeeman reducer can be used.

[0092] In the above embodiments, a Zeeman reducer is used to slow down the atomic beam emitted from the nuclear reactor. However, this is not a limitation; for example, if a low-speed atomic beam is supplied, a Zeeman reducer is not required.

[0093] The atom trapping unit 16 includes a vacuum chamber in which a trapping region for trapping atoms is formed. An atomic beam traveling from the Zeeman decelerator 14 to the atom trapping unit 16 is trapped by the atom trapping unit 16. Specifically, the atom trapping unit 16 includes multiple optical elements and a magnetic field generating unit 22, the multiple optical elements forming a laser beam group 18.

[0094] Multiple optical elements, including a light source, a λ / 4 mirror (λ / 4 mirror) 20, and a beam splitter, irradiate a laser beam group 18 from six directions toward a zero magnetic field position in order to impart restorative force to atoms through radiation pressure. The laser beam group 18 includes: a laser beam traveling in the x-direction along the x-axis, a laser beam traveling in the opposite -x-direction, a laser beam traveling in the y-direction along the y-axis, a laser beam traveling in the opposite -y-direction, a laser beam traveling in the z-direction along the z-axis, and a laser beam traveling in the opposite -z-direction. A λ / 4 mirror 20 is provided on the z-axis. The laser beam traveling in the -z-direction is formed by the laser beam traveling in the z-direction and the λ / 4 mirror 20. That is, the laser beam traveling in the z-direction is reflected by the λ / 4 mirror 20, thereby forming a laser beam traveling in the -z-direction.

[0095] Reference Figures 5-10The magnetic field generating unit 22 will be described below. The magnetic field generating unit 22 includes coils 222A and 222B, and a conical solenoid coil 223, generating a quasi-three-dimensional quadrupole magnetic field. Coils 222A and 222B have approximately the same shape and size. The tips of coils 222A and 222B taper as they travel in the direction in which atoms are guided (y-axis direction). The winding density of coils 222A and 222B becomes looser (spiral) as they travel in the direction in which atoms are guided. Coils 222A and 222B are arranged relative to each other such that the distance between them decreases as they travel in the direction in which atoms are guided. Coils 222A and 222B are conically arranged relative to the xy plane formed by the x-axis and y-axis, respectively. The conical solenoid coil 223 is sandwiched between coils 222A and 222B, or disposed outside coils 222A and 222B.

[0096] The λ / 4 reflector 20 is positioned outside the coil to avoid blocking the laser beams traveling in the x-direction, -x-direction, y-direction, and -y-direction. To avoid degrading the optical characteristics of the λ / 4 reflector 20, it can also be fixed to a location outside the light-receiving part (e.g., at the four corners). Alternatively, the λ / 4 reflector 20 can be configured not to directly contact the magnetic field generating part 22.

[0097] Laser beam 28 is a narrow-linewidth cooling laser beam irradiated from light source 29, with a wavelength of 2.9 μm. Laser beam 28 irradiates in the +y direction along the y-axis. As a result, atoms are trapped near position 30 where magnetic force, gravity, and the radiation pressure of laser beam 28 are in equilibrium.

[0098] Alternatively, the laser beam 28 can be incident bidirectionally from the +y axis and the -y axis to cool the atom clusters at the equilibrium point of magnetic force and gravity.

[0099] Figure 11 (a) is a plan view of the magnetic field generating part 22 as viewed from the +z direction. Figure 11 (b) represents the absolute value of the magnetic field strength along the y-axis and the resultant force of the magnetic force and gravity acting on the atoms. The magnetic field along the y-axis passes through a zero point near y = 20 mm, forming a MOT region around this zero point. A spherical quadrupole magnetic field is formed within this region. Outside the MOT region (the region where the y value is greater than that of the MOT region), the magnetic field gradient is weaker, forming a magnetic field guide for the atoms (magnetic trap region). A linear quadrupole magnetic field with a bias magnetic field is formed within this region. The magnetic field gradually weakens within the MOT region. 3 Atoms in the P2 state move in the +y direction under the combined force of magnetic force and gravity. In this system, the final trapping position is achieved near y=67mm due to the potential barrier formed by the magnetic field trap, around y=70mm.

[0100] exist Figure 11 In system (a), consider the case where a current of 3A is applied to a coil with a total of 30 turns. In this case, the calculated magnetic field gradient near the MOT location is approximately 30 G / cm along the x-axis and approximately 10 G / cm along the y-axis. Therefore, it can be concluded that in... Figure 11 (a) The system can implement MOT.

[0101] Figure 12 Indicates by Figure 11 (a) Contour lines of the leakage magnetic field generated by the system. Figure 12 (a) is the yz plane at x=0. Figure 12 (b) shows the xy-plane at z=0. In these diagrams, the magnetic field is shown up to 10G in steps of 1G; areas exceeding 10G are indicated in white. Figure 12 (a) and Figure 12 In (b), the area shown by the darker shaded line at the top (located more than 2 cm from the magnetic field generator) has a magnetic field strength of less than 1 G, making it a suitable region for spectral dispersion. In contrast, for example, when using a magnetic rod to form a quasi-three-dimensional quadrupole magnetic field, a leakage magnetic field of approximately 10 G is generated at a position approximately 2 cm away from the magnetic rod. This makes spectral dispersion difficult. According to this embodiment, this problem can be solved. Furthermore, in Figure 12 (a) and Figure 12 (b) also shows a spherical quadrupole magnetic field for achieving MOT, a linear quadrupole magnetic field with a biased magnetic field suitable for magnetic field guidance of atoms, and the final trapping position of atoms.

[0102] [Implementation of the Magnetic Field Generating Unit] Next, use Figure 13 An implementation example of the magnetic field generating unit in the embodiment will be described. Figure 13 In the example, a spiral coil (e.g., Figure 5 The coil 222 shown is made using a multilayer PCB (printer circuit board) substrate. The main body of the multilayer PCB substrate, sandwiched between two such substrates, is made of thermally conductive metals such as Al and Cu. This allows for heat dissipation from the multilayer PCB. Holes are provided on the multilayer PCB substrate and the main body for the passage of the desired optical path.

[0103] As a consideration during implementation, the heat dissipation of the multilayer PCB substrate is examined. If the width of the current path on the PCB substrate is set to constant, the power loss of the PCB substrate is inversely proportional to the thickness of the copper foil forming the substrate. For example, using the commonly used 35μm thick copper foil, the estimated power loss is approximately 24W. Using 105μm thick copper foil, the power loss is reduced to approximately 8W, enabling a structure with no heat dissipation issues. Even lower power consumption can be achieved by further increasing the copper foil thickness.

[0104] Figure 14 This example illustrates a magnetic field generating section composed of four multilayer PCB substrates A, B, C, and D. A helical coil is formed on the upper multilayer PCB substrate A and the lower multilayer PCB substrate C. A tapered solenoid coil is formed on the upper multilayer PCB substrate A, the lower multilayer PCB substrate C, and the side multilayer PCB substrates B and D. Substrates A and C are 10-layer PCB substrates with approximately the same pattern. Substrates B and D are double-sided PCB substrates with approximately the same pattern. This configuration forms a 9-turn helical coil and a 9-turn tapered solenoid coil.

[0105] Table 1 shows the wiring of the coils forming a magnetic field generating section of a multilayer (10-layer) PCB substrate, with layers numbered from the first to the tenth layer from the bottom. Figure 15 As an example, a coil wired to the first layer of the multilayer PCB substrate is shown.

[0106] [Table 1]

[0107] [Variation Example] Figure 16 This is a schematic diagram of a modified magnetic field generating unit. In the example above, the magnetic field generating unit consists of a helical coil and a conical solenoid coil. Alternatively, it can also use... Figure 16 The coil shown in the diagram constitutes the magnetic field generating part. By moving along the direction of the arrow... Figure 16 When current is passed through the coil, it can simultaneously generate a quadrupole magnetic field and cancel out the magnetic field in the y-axis direction. Figure 16 The coil is called a "baseball coil" because it resembles the stitching on a baseball ball.

[0108] The magnetic field generating unit can also be constructed by combining a spiral coil and a conical solenoid coil with a baseball coil.

[0109] As described above, according to this embodiment, an atom trapping device can be provided that generates a compact quasi-three-dimensional quadrupole magnetic field to realize MOT and subsequent magnetic traps while minimizing the generated leakage magnetic field.

[0110] [Second Implementation] The second embodiment of this disclosure is an atomic cooling device. To guide the atomic gas to subsequent devices, the following measures are taken to maximize... 3 The number of atoms in the P2 state and cooling 3 Atoms in the P2 state are valid.

[0111] As an increase 3 One method for determining the number of atoms in the P2 state is to use a 461nm wavelength laser, by employing...1 S0- 1 The magneto-optical trap excited between P1 is then... 1 The D2 condition has eased to 3 The method for P2 state.

[0112] To further cool the magnetic field trapped by the magnetic field 3 For atoms in the P2 state, consider performing an energy difference equivalent to a 2.9 μm wavelength. 3 P2- 3 Excited Doppler cooling between D3. Due to the low transition linewidth of 57 kHz during this period, cooling temperatures down to a few microKelvin can be achieved (e.g., see Non-Patent Documents 4 and 7). The achievable cooling temperature in the magnetic field trap is represented by the following equation (3).

[0113] [Formula 5] …(3) Here, T D The theoretical cooling temperature, known as the Doppler temperature, is represented by the following equation (4).

[0114] [Formula 6] …(4) γ IR For the transition line width. is Planck's constant.

[0115] f0 is the magnetic gravity F BG With maximum radiation pressure F R The ratio is expressed by the following formula (5).

[0116] [Formula 7] …(5) The atomic cooling apparatus associated with the second embodiment includes the atomic trapping apparatus of the above embodiment (e.g., atomic trapping apparatus 10). In addition to the operations S1 to S3 of the atomic trapping apparatus, the atomic cooling apparatus also performs the following steps.

[0117] S4: Yes 3 Atoms in the P2 state undergo narrow-linewidth cooling.

[0118] S5: Cooled atoms are guided to subsequent devices by moving the optical lattice or optical dipole. At this point, they can also be optically pumped to a third state that is insensitive to magnetic fields.

[0119] In step S4, for 3 Atoms in the P2 state are irradiated with 3 P2- 3A 2.9 μm laser beam resonates between the D3 states, thus performing Doppler cooling. This reduces the temperature of the atoms to approximately a few microKelvin. It can also be used for... 3 The D3 state introduces optical lattice potential energy and uses the Sisyphus process to enhance the cooling efficiency of atoms (e.g., see Non-Patent Literature 8).

[0120] In step S5, the position where the atom is finally trapped is connected to the input section of the subsequent device (the location where the cooled atom is input) by optical dipole guidance. Alternatively, the cooled atom can be guided to the subsequent device by optically pumping it to a state insensitive to a magnetic field. For example, a moving optical lattice technique (e.g., see Patent Document 3) can be used to move the cooled atom from its trapped position to the input section of the subsequent device. The third state can also be... 3 m in state P2 j =0 magneton level 3 P0 state or 1 S0 state.

[0121] According to this embodiment, it is possible to effectively cool magnetically trapped atoms.

[0122] In the above embodiments, the magnetically trapped atoms were cooled by Doppler cooling. However, the cooling method is not limited to Doppler cooling. For example, a Sisyphus cooling mechanism can be used instead of a Doppler cooling mechanism.

[0123] [Third Implementation Method] The third embodiment of this disclosure is a spectrophotometer. This spectrophotometer includes the atomic cooling device and the spectrophotometer section of the above embodiments. The spectrophotometer section is located in a region where the leakage magnetic field from the magnetic field generating unit 22 is sufficiently weak (e.g., a region where the leakage magnetic field is below 1 G). Atoms cooled by the atomic cooling device are guided to the spectrophotometer section for spectrophotometer separation.

[0124] According to this embodiment, a compact spectrometer capable of performing spectroscopy in an environment with a weak leakage magnetic field can be provided.

[0125] Figure 18 The above embodiment is illustrated schematically. Starting from the position where the atom is finally trapped, the atom... 3 The P2 state is extracted by a moving optical lattice. Incident excitation is coaxial with this moving optical lattice. 1 S0- 3 The laser beam splits the P0 clock transition. Atoms are optically pumped to P0 by the optically pumped laser 1. 3 The P0 state defines the starting point of the spectral splitting region. As atoms move within this region, they interact with the laser used for splitting, evolving over time into… 1 S0 state and 3The superposition of P0 states. Optically pumped laser 2 will... 3 Atom light pumping to P0 state 3 P2 state, thereby through the 1 S0- 3 The endpoint of the spectroscopic region is defined by the projection measurement of the P0 clock transition. The atomic number determination laser uses... 3 P2- 3 Laser-induced fluorescence pairs of D3 transitions 3 Atoms in the P2 state were measured to determine... 3 Excitation rate of the P0 state.

[0126] According to this embodiment, laser beams and laser-induced fluorescence that could cause clock transitions or optical shifts can be prevented from intruding into the spectroscopic region, thus achieving high-precision spectroscopic measurements. Furthermore, this method achieves spectroscopic measurements without dead time or invalid time.

[0127] The optical pumping state is arbitrary. For example, it can also be pumped to a state that is optically pumped by laser 1. 1 In state S0, the optically pumped laser 2 will... 3 Atom light pumping to P0 state 3 P2 state. In this case, the atomic number determination laser also passes through... 3 P2- 3 Laser-induced fluorescence pairs of D3 transitions 3 Atoms in the P2 state were measured to determine... 3 Excitation rate of the P0 state.

[0128] Spectroscopic lasers can also be clock-transition lasers.

[0129] The above methods all achieve time-free beam splitting of atoms within the beam splitting region (longitudinal excitation beam splitting), realizing a high-precision and high-stability optical lattice clock.

[0130] [Fourth Implementation Method] The fourth embodiment of this disclosure is an optical lattice clock. This optical lattice clock includes the atomic cooling device of the above embodiments.

[0131] Figure 17 This is a functional block diagram of the optical lattice clock 200 related to this embodiment. The optical lattice clock 200 includes a physical package 202, an optical system device 204, a control device 206, and a PC (control computer) 208. The physical package 202 includes an atomic cooling device 2021 and a clock transition excitation unit 2022. The atomic cooling device 2021 is the atomic cooling device of the above embodiment.

[0132] The physical package 202 is a device that confines cooled atomic clusters within an optical lattice and induces clock transitions. The optical system device 204 is a device equipped with optical devices such as a laser source for atomic cooling, a laser source for atomic trapping, a laser source for exciting clock transitions, and a laser frequency control device. In addition to sending a laser beam to the physical package 202, the optical system device 204 also excites clock transitions within the physical package 202 using Rabi or Ramsey spectroscopy, and then measures the electronic states of the atoms using projection measurement. The signal from the projection measurement is received, converted into an electrical signal, and fed back to the laser source to match its resonant frequency with that of the atoms. The control device 206 is a device that controls the physical package 202 and the optical system device 204. The control device 206 performs operations such as controlling the movement of the physical package 202, controlling the movement of the optical system device 204, and analyzing the frequency of the measured clock transitions. The physical package 202, the optical system device 204, and the control device 206 cooperate to realize the function of the optical lattice clock 200.

[0133] PC208 is a general-purpose computer including a processor and memory. The functions of PC208 are realized by running software through the hardware including the processor and memory. An application program for controlling the optical lattice clock 200 is installed on PC208. PC208 is connected to the control device 206, and can control not only the control device 206, but also the entire optical lattice clock 200, including the physical package 202 and the optical system device 204. In addition, PC208 provides the UI (user interface) for the optical lattice clock 200. Users can perform functions such as excitation, time measurement, and result confirmation of the optical lattice clock 200 via PC208.

[0134] In the physical package 202, the atomic clusters cooled by the atomic cooling device 2021 are moved to the clock transition beam splitting region of the clock transition excitation unit 2022.

[0135] In the clock transition space, a frequency-controlled laser beam is irradiated onto atoms to perform high-precision beam splitting of clock transitions (i.e., resonant transitions of atoms that serve as clock references), thereby measuring the inherent and unchanging frequencies of the atoms. This allows for the realization of an accurate atomic clock.

[0136] To improve the accuracy of atomic clocks, it is necessary to eliminate perturbations around the atoms and accurately read their frequencies. Crucially, this involves eliminating the frequency shift caused by the Doppler effect resulting from the thermal motion of atoms. In optical lattice clocks, atoms are confined within a space much smaller than the wavelength of the clock laser by using an optical lattice formed by laser beam interference, thus quantizing atomic motion. However, within the optical lattice, the laser beam forming the lattice causes a frequency shift in the atoms. Therefore, by selecting a specific wavelength and frequency, known as the "magic wavelength" or "magic frequency," as the optical lattice beam, the influence of the optical lattice on the clock transition frequencies of the atoms is eliminated.

[0137] The light emitted by the clock transition is received by the optical system device 204, and the control device 206 performs beam splitting operations to determine the frequency.

[0138] According to this embodiment, a compact optical lattice clock can be provided.

[0139] Figure 19 The above-described embodiments are illustrated schematically.

[0140] [Fifth Implementation Method] The fifth embodiment of this disclosure is a quantum computer. This quantum computer includes the atomic cooling device described in the above embodiments.

[0141] This quantum computer includes a physical package, an optical system, a control unit, and a PC. The physical package includes an atomic cooling device and a clock transition excitation unit. The atomic cooling device is the same as described in the above embodiment. The clock transition excitation unit is configured to correspond to the operation of the qubits.

[0142] According to this embodiment, a compact quantum computer with highly scalable qubits can be realized.

[0143] [Sixth Implementation Method] The sixth embodiment of this disclosure is a coil. This coil is... Figure 5 The coil shown is a spiral coil. That is, the coil is a spiral coil that tapers at the front end and the winding density decreases as it moves forward.

[0144] According to this embodiment, a compact quasi-three-dimensional quadrupole magnetic field can be generated for realizing MOT and subsequent magnetic traps.

[0145] [Seventh Implementation Method] The seventh embodiment is an atomic trapping method. This atomic trapping method uses an atomic trapping apparatus equipped with an atomic furnace and an atomic trapping unit to trap atoms. The method includes: a step of generating atomic gas using an atomic furnace; a step of magneto-optical trapping of atoms using the atomic trapping unit; and a step of magnetically trapping and guiding atoms using the atomic trapping unit. The atomic trapping unit includes multiple optical elements and a magnetic field generating unit, the multiple optical elements forming a laser beam. The magnetic field generating unit includes at least two helical coils and a conical solenoid coil. The helical coils are configured such that their tips become thinner and their winding density becomes looser as they travel in the direction in which the atoms are guided. The helical coils are arranged opposite each other such that the distance between them decreases as they travel in the direction in which the atoms are guided. The conical solenoid coil generates a magnetic field to counteract the component of the magnetic field generated by the helical coils in the direction in which the atoms are guided.

[0146] [Eighth Implementation Method] The eighth embodiment is an atomic cooling method. This atomic cooling method uses an atomic cooling apparatus equipped with the atomic cooling device and Doppler cooling mechanism described in the second embodiment to capture atoms. The method includes: generating atomic gas using an atomic furnace; performing magneto-optical capture of atoms using an atomic capture unit; performing magnetic capture and guiding of atoms using the atomic capture unit; and performing Doppler cooling of the guided atoms using the Doppler cooling mechanism.

[0147] [Ninth Implementation Method] The ninth embodiment is a spectrophotometric method. This spectrophotometric method uses the atomic cooling apparatus described in the second embodiment for spectrophotometric separation. The method includes: generating atomic gas using an atomic furnace; magneto-optical trapping of atoms using an atomic trapping unit; magnetic trapping and guiding of atoms using the atomic trapping unit; and Doppler cooling of the guided atoms using a Doppler cooling mechanism.

[0148] As described above, the present invention has been illustrated based on embodiments. These embodiments are merely illustrative, and those skilled in the art should understand that various modifications can be made to the combination of the above-described constituent elements or operational processes, and such modifications also fall within the scope of the present invention.

[0149] When understanding the technical ideas abstracted from the implementation methods and variations, these ideas should not be limited to the content of the implementation methods and variations. The above-mentioned implementation methods and variations are merely specific examples, and various design changes such as alterations, additions, and deletions of constituent elements are permissible. In the implementation methods, the content that allows for such design changes is emphasized by the term "implementation method." However, design changes are permitted even without such a description.

[0150] Industrial applicability This invention can be used in atomic trapping devices, atomic cooling devices, spectrophotometers, optical lattice clocks, quantum computers, coils, atomic trapping methods, atomic cooling methods, and spectrophotometer methods.

[0151] Explanation of reference numerals in the attached figures 10 Atom Trapping Device 12 nuclear reactors 14. Zeeman reducer 14b Laser beam used for Zeeman deceleration 16 Atom Capture Unit 18 laser beam groups 20 λ / 4 reflector 28 laser beams 29 Light Source 221A Trapezoidal Coil 221B Trapezoidal Coil 222 Spiral coil 222A Spiral Coil 222B Spiral Coil 223 Tapered solenoid coil S1 is the step of supplying low-speed atoms. S2 Steps for performing MOT using a quasi-three-dimensional quadrupole magnetic field S4 Steps for performing magnetic guidance using a quasi-three-dimensional quadrupole magnetic field S4 performs the Doppler cooling procedure. S5 is the step of guiding cooled atoms to subsequent devices.

Claims

1. An atom trapping device, said atom trapping device for trapping atoms, characterized in that, The atom trapping device comprises: An atomic trapping section, wherein an atomic gas beam is incident, The atom trapping unit includes multiple optical elements and a magnetic field generating unit, and the multiple optical elements form a laser beam group. The magnetic field generating unit has at least two helical coils and a conical solenoid coil. The spiral coil is configured such that as it travels in the direction in which the atoms are guided, the tip becomes thinner while the winding density becomes looser. The spiral coils are arranged such that the distance between them decreases as they travel in the direction in which the atom is guided. The conical solenoid coil generates a magnetic field to adjust the component of the magnetic field generated by the helical coil in which the atoms are guided.

2. The atom trapping device according to claim 1, characterized in that, The magnetic field generating unit forms the following magnetic field distribution: a first region with a large magnetic field gradient for realizing a magneto-optical trap, and a second region with a small magnetic field gradient in the guiding direction for realizing magnetic field guidance of atoms.

3. The atom trapping device according to claim 2, characterized in that, The magnetic field distribution is a quasi-three-dimensional quadrupole magnetic field. The quasi-three-dimensional quadrupole magnetic field is a spherical quadrupole magnetic field in the first region and a linear quadrupole magnetic field with a bias magnetic field in the second region.

4. The atom trapping device according to claim 3, characterized in that, The atom trapping device includes a magnetic field trap that traps the guided atoms into a final trapping region.

5. The atom trapping device according to claim 4, characterized in that, The volume of the first region is 1000 mm. 3 The volume of the final capture area is 1 mm. 3 the following.

6. The atom trapping device according to claim 1, characterized in that, At a position 2 cm or more from the magnetic field generating part, the intensity of the leakage magnetic field from the magnetic field generating part is less than 1 G.

7. The atom trapping device according to claim 1, characterized in that, The atoms are guided in the direction of gravity.

8. The atom trapping device according to claim 1, characterized in that, The spiral coil and the conical solenoid are made of multilayer PCB substrate.

9. The atom trapping device according to claim 1, characterized in that, The magnetic field generating unit includes a baseball coil.

10. An atomic cooling device, characterized in that, The atomic cooling device comprises the atomic trapping device and the Doppler cooling mechanism as described in claim 1.

11. An atomic cooling device, characterized in that, The atomic cooling device comprises the atomic trapping device as described in claim 1, and a Sisyphus cooling mechanism.

12. A spectrophotometer, characterized in that, The spectrophotometer includes the atomic cooling device and the spectrophotometer as described in claim 10 or 11.

13. An optical lattice clock, wherein the optical lattice clock comprises physical packaging, an optical system device, a control device, and a PC, characterized in that, The physical package includes the atomic cooling device and clock transition excitation unit as described in claim 10.

14. A quantum computer, comprising physical packaging, an optical system, a control device, and a PC, characterized in that, The physical package includes the atomic cooling device as described in claim 10 and a clock transition excitation unit corresponding to the operation of the qubit.

15. A spiral coil, wherein the spiral coil is configured such that as it moves forward, the front end becomes thinner while the winding density becomes looser.

16. An atomic trapping method, wherein the atomic trapping method uses an atomic trapping device equipped with an atomic trapping section to trap atoms, characterized in that, include: The steps of supplying atoms; The step of using the atom trapping unit to perform magneto-optical trapping of the atoms; as well as The step of using the atom trapping unit to magnetically trap and guide the atoms. The atom trapping unit includes multiple optical elements and a magnetic field generating unit, and the multiple optical elements form a laser beam group. The magnetic field generating unit has at least two helical coils and a conical solenoid coil. The spiral coil is configured such that as it travels in the direction in which the atoms are guided, the tip becomes thinner while the winding density becomes looser. The spiral coils are arranged such that the distance between them decreases as they travel in the direction in which the atom is guided. The conical solenoid coil generates a magnetic field to adjust the component of the magnetic field generated by the helical coil in which the atoms are guided.

17. The atomic trapping method according to claim 16, characterized in that, The magnetic field generating unit includes a baseball coil, which replaces the spiral coil and the conical solenoid coil.

18. An atomic cooling method, wherein the cooling method uses the atomic cooling apparatus of claim 10 to cool atoms, characterized in that, include: The steps of supplying atoms; The step of using the atom trapping unit to perform magneto-optical trapping of the atoms; The steps of magnetically trapping and guiding the atoms using the atom trapping unit; and The step of using the Doppler cooling mechanism to perform Doppler cooling on the guided atoms.

19. An atomic cooling method, wherein the cooling method uses the atomic cooling apparatus of claim 11 to cool atoms, characterized in that, include: The steps of supplying atoms; The step of using the atom trapping unit to perform magneto-optical trapping of the atoms; The steps of magnetically trapping and guiding the atoms using the atom trapping unit; and The step of using the Sisyphus cooling mechanism to perform Doppler cooling on the guided atoms.

20. A spectroscopic method, wherein the spectroscopic method uses a spectroscopic apparatus having the atomic cooling device and the spectroscopic section as described in claim 10 to perform spectroscopic dispersion, characterized in that, include: The steps of supplying atoms; The step of using the atom trapping unit to perform magneto-optical trapping of the atoms; The step of magnetically capturing and guiding the atoms using the atom capturing unit; The step of using the Doppler cooling mechanism to perform Doppler cooling on the guided atoms; as well as The step of using the aforementioned beam-splitting unit to perform beam splitting.

21. A spectroscopic method, wherein the spectroscopic method uses a spectroscopic apparatus having the atomic cooling device and the spectroscopic section as described in claim 11 to perform spectroscopic dispersion, characterized in that, include: The steps of supplying atoms; The step of using the atom trapping unit to perform magneto-optical trapping of the atoms; The step of magnetically capturing and guiding the atoms using the atom capturing unit; The step of using the Sisyphus cooling mechanism to perform Doppler cooling on the guided atoms; as well as The step of using the aforementioned beam-splitting unit to perform beam splitting.

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