Cooling atom generation device, cooling atom generation method, physical package, physical package for optical lattice clock, physical package for atomic clock, physical package for atom interferometer, physical package for quantum information processing device, and physical package system

Abstract

In a first region in which atoms in a first state are captured by first light and a magnetic field, the atoms are optically pumped to a second state, and the atoms are captured by magnetic force. The atoms in the second state trapped in the first region are moved from the first region to the second region by gravity or radiation pressure of the second light. In the second region, the atoms in the second state are cooled by irradiating the atoms in the second state with the second light. By optically pumping the atoms into a third state that is insensitive to the magnetic field, the atoms are released from the magnetic trap and supplied to a subsequent device by moving the optical lattice or optical dipole guide.

Description

Technical Field

[0001] The present invention relates to a cooling atom generating device, a cooling atom generating method, a physical package, a physical package for an optical lattice clock, a physical package for an atomic clock, a physical package for an atom interferometer, a physical package for a quantum information processing device, and a physical package system. Background Art

[0002] The optical lattice clock is an atomic clock proposed by Hidetoshi Katori, one of the inventors of this application, in 2001. In the optical lattice clock, atomic groups are enclosed in an optical lattice formed by lasers, and the resonant frequency in the visible light region is measured. Therefore, it is possible to measure with an accuracy of 18 bits, which is far higher than the accuracy of the current cesium clock. Optical lattice clocks are being researched and developed not only by the inventor group, but also by various groups at home and abroad, and are being developed into the next generation of atomic clocks.

[0003] As for the recent technology of optical lattice clocks, for example, the following patent documents 1 to 3 can be cited. Patent document 1 describes the formation of a one-dimensional moving optical lattice inside an optical waveguide having a hollow channel. Patent document 2 describes a scheme for setting an effective magic frequency. In fact, the magic wavelength has been determined theoretically and experimentally using strontium, ytterbium, mercury, cadmium, and magnesium. In addition, patent document 3 describes a radiation shield that reduces the influence of black body radiation emitted from the surrounding walls.

[0004] In an optical lattice clock, time is measured with high precision, so a height difference of 1 cm on the earth based on the general relativity effect of gravity can be detected as a deviation in the time process. Therefore, if the optical lattice clock can be miniaturized and portable and used in the field outside the laboratory, the applicability will be expanded to new geodetic technologies such as underground resource exploration, underground caves, and magma chamber detection. By mass-producing optical lattice clocks and deploying them in various places, it is possible to continuously monitor the time changes of gravitational potential, detect crustal changes, and spatial mapping of gravity fields. In this way, optical lattice clocks are expected to exceed the limits of high-precision time measurement and contribute to society as a new basic technology.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6206973

[0008] Patent Document 2: Japanese Patent No. 6635608

[0009] Patent Document 3: Japanese Patent No. 7189588 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] However, in devices such as atomic clocks and atomic interferometers, it is desirable to continuously supply cooled atomic gas and continuously perform measurements. However, when the atomic gas is retained in the same place, it is impossible to perform multiple different treatments on the atomic gas, resulting in difficulty in continuously supplying the atomic gas to subsequent devices.

[0012] An object of the present invention is to continuously cool atoms and continuously supply them to a subsequent device.

[0013] Solutions for solving problems

[0014] One scheme of the present invention is a cooling atom generating device, characterized in that it includes: a first cooling unit, which cools and captures atoms in a first state by a first light and a magnetic field in a first region; a magnetic trap unit, which captures atoms optically pumped to a second state by magnetic force; a second cooling unit, which cools the atoms in the second state by irradiating the atoms in the second state moved from the first region to the second region with a second light; and a supply unit, which supplies atoms to a subsequent device by optically pumping the atoms to a third state insensitive to a magnetic field in the second region using a moving optical lattice or an optical dipole guide. Here, the atoms in the second state refer to atoms whose total orbital angular momentum J is not zero and have a magnetic quantum number m that decreases the Zeeman energy for a weak magnetic field. J atoms, that is, atoms in a weak field seeking state.

[0015] In the above-mentioned structure, atoms in the first state are cooled and captured in the first region, and atoms in the second state after optical pumping are magnetically captured and moved to a second region different from the first region. In the second region, the atoms in the second state are cooled by irradiating the second light to the atoms. In this way, by capturing and cooling atoms in different states and places, it is possible to capture and cool atoms continuously. As a result, atoms can be continuously cooled and supplied to the subsequent device. For example, the above-mentioned magnetic field is a quadrupole magnetic field. Atoms in the first state are magneto-optically captured at or around a position where the quadrupole magnetic field is zero. Atoms that are optically pumped to a second state that is sensitive to magnetism are magnetically captured by the quadrupole magnetic field. In the second region that does not include a position where the quadrupole magnetic field is zero (that is, the region where the atoms are moving to), the atoms are cooled by the second light (for example, a laser for narrow linewidth cooling).

[0016] Alternatively, three mutually orthogonal axes are determined, and the magnetic trap unit moves atoms from the first region to the second region by forming a magnetic field distribution in which the magnetic field gradient in the direction of one of the three axes is weaker than the magnetic field gradients in the directions of the other two axes.

[0017] The one axial direction may be a direction in which gravity acts, and the second region may be a position where the magnetic force, gravity, and radiation pressure of the second light are balanced.

[0018] The one axial direction may be a direction in which gravity does not act, and the second region may be a position where the magnetic force and the radiation pressure of the second light are balanced.

[0019] The one axial direction may be a direction in which the radiation pressure of the second light acts, and the second region may be a position where the magnetic force and the radiation pressure of the second light are balanced.

[0020] Alternatively, the magnetic trap unit may include a coil and a permanent magnet, and the magnetic field distribution is formed by a magnetic field from the coil and a magnetic field from the permanent magnet. Alternatively, the magnetic trap unit may include a permanent magnet, and the magnetic field distribution is formed in the first region by the permanent magnet.

[0021] Alternatively, the magnetic trap unit includes a permanent magnet that forms a two-dimensional quadrupole magnetic field on a plane defined by the two axes and a coil that forms a magnetic field in the direction of the one axis, and the magnetic field distribution is formed by the magnetic field from the permanent magnet and the magnetic field from the coil.

[0022] Alternatively, the atom is a strontium atom, and the energy level of the atom is 3 P2 energy level. Alternatively, the atom is a calcium (Ca) atom or an ytterbium (Yb) atom.

[0023] Alternatively, the first light may be a laser with a wavelength of 461 nm, and the first state may be 5 s. 21 S0 state.

[0024] Alternatively, the second light may be a laser with a wavelength of 2.9 μm, and the second state may be 5s5p 3 P2 status.

[0025] Alternatively, the coil and the permanent magnet generate a quadrupole magnetic field in the first region with the zero magnetic field position as the center in such a manner that a magneto-optical trap is realized for the atoms in the first state by the first cooling unit, and form a magnetic field distribution in the second region in such a manner that the sum of the gravity acting on the atoms and the radiation pressure of the second light is balanced with the magnetic force acting on the atoms, and the magnetic field distribution formed in the second region is formed by a non-zero finite magnetic field and realizes a magnetic field distribution of a magnetic trap while preventing Majorana flipping.

[0026] Alternatively, the first region and the second region are sufficiently separated from each other in space. Alternatively, the second region and the subsequent device are sufficiently separated from each other in space. Alternatively, the straight line connecting the first region and the second region and the straight line connecting the second region and the subsequent device are not on the same straight line. As required, a light-blocking element (for example, a light-blocking wall such as a wall that does not transmit light) may be provided between the first region and the subsequent device. By blocking the straight path connecting the magneto-optical trap provided in the first region and the subsequent device, it is possible to avoid the natural emitted light generated in the magneto-optical trap from acting on the subsequent devices such as an atom interferometer and an atomic clock to generate an optical frequency shift of a clock transition.

[0027] In order to spatially separate the first region from the subsequent device, two moving optical lattices crossing at a non-zero angle may be used. Here, one moving optical lattice passes through the second region, and the other moving optical lattice passes through the subsequent device. The former is referred to as the first moving optical lattice, and the latter is referred to as the second moving optical lattice.

[0028] In the second region, atoms are optically pumped to a third state that is insensitive to a magnetic field and are captured by the first moving optical lattice. The captured atoms are guided by the first moving optical lattice and move to a point where they intersect with the second moving optical lattice at a non-zero angle. At the point of intersection, atoms captured by the first moving optical lattice or a portion of atoms captured by the first moving optical lattice are transferred to the second moving optical lattice and captured by the second moving optical lattice. Atoms captured by the second moving optical lattice are guided by the second moving optical lattice and move to a subsequent device. As a result, the first region is spatially separated from the subsequent device, or it is possible to suppress the naturally emitted photons generated in the first region from intruding into the subsequent device. Alternatively, the moving optical lattice is formed by a bow-tie resonator. Alternatively, the second region and the subsequent device are optically connected through a plurality of moving optical lattices connected by a common intersection.

[0029] In addition, the cooling atom generating device may further include a light shielding wall that optically shields the first region from the subsequent device, and the light shielding wall suppresses the incidence of the natural emission light generated in the first region on the subsequent device.

[0030] One scheme of the present invention is a cooling atom generating device, comprising: a first cooling unit, which cools and captures atoms in a first state in a first region by means of a first light and a magnetic field; a unit that relaxes the state of atoms captured in the first region to a second state by means of optical pumping generated during laser cooling; a unit that moves atoms to a second region where the magnetic field is non-zero by means of a balance between the magnetic force, gravity, and radiation pressure of a second light irradiated to the atoms in the second state acting on the atoms in the second state; a second cooling unit, which cools the atoms in the second state by irradiating the atoms in the second state with a second light in the second region; and in the second region, optically pumps the atoms to be insensitive to the magnetic field. a unit for supplying atoms in the third state from the second region to a subsequent device by moving an optical lattice or an optical dipole guide, the atoms in the first state input to the first region are cooled by the first cooling unit and transition to the second state, the atoms in the second state move from the first region to the second region by a balance among the magnetic force, gravity and the radiation pressure of the second light, the state of the atoms moved to the second region is changed to the third state by performing an optical pumping operation after being cooled by the second cooling unit, the atoms in the third state are captured by the moving optical lattice or the optical dipole guide and supplied from the second region to the subsequent device.

[0031] One scheme of the present invention is a method for generating cooled atoms, characterized in that it includes: a first cooling step, in a first region, cooling and capturing atoms in a first state by a first light and a magnetic field; a magnetic trap step, capturing atoms optically pumped to a second state by magnetic force; a step of moving atoms from the first region to a second region; a second cooling step, cooling the atoms in the second state by irradiating the atoms in the second state with a second light; and a supply step, in the second region, optically pumping the atoms to a third state that is insensitive to a magnetic field, thereby supplying the atoms to a subsequent device using a moving optical lattice or an optical dipole guide.

[0032] Alternatively, three mutually orthogonal axes are determined, and in the magnetic trap step, a magnetic field distribution is formed in which the magnetic field gradient in the direction of one of the three axes is weaker than the magnetic field gradients in the directions of the other two axes, so that gravity or the radiation pressure of the second light can be used to move atoms from the first region to the second region.

[0033] One embodiment of the present invention is a physical package, characterized by comprising: the above-mentioned cooling atom generating device; and a vacuum chamber that surrounds a clock transition space in which atoms are arranged.

[0034] One embodiment of the present invention is a physical package for an optical lattice clock, characterized by including the above-mentioned physical package.

[0035] One embodiment of the present invention is a physical package for an atomic clock, characterized by including the above-mentioned physical package.

[0036] One embodiment of the present invention is a physics package for an atom interferometer, characterized by including the above-mentioned physics package.

[0037] One embodiment of the present invention is a physical package for a quantum information processing device for atoms or ionized atoms, characterized by including the above-mentioned physical package.

[0038] One aspect of the present invention is a physical packaging system, comprising: the above-mentioned physical packaging; and a control device that controls the operation of the physical packaging.

[0039] Effects of the Invention

[0040] According to the present invention, atoms can be continuously cooled and continuously supplied to a subsequent device. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a diagram showing the energy levels of strontium atoms.

[0042] Figure 2 It is a diagram showing the cooling atom generation method according to the first embodiment.

[0043] Figure 3 It is a diagram showing the cooling atom generation method according to the second embodiment.

[0044] Figure 4 This is a perspective view showing the cooling atom generating device according to the first embodiment.

[0045] Figure 5 It is a perspective view showing the magneto-optical trap device (MOT device) according to the first embodiment.

[0046] Figure 6 This is a diagram of the magneto-optical trap device according to the first embodiment as viewed from the -Z direction.

[0047] Figure 7 This is a diagram of the magneto-optical trap device according to the first embodiment as viewed from the Y direction.

[0048] Figure 8It is a diagram showing the calculation results of trapped atoms and magnetic field components in various directions.

[0049] Fig. 9A It is a diagram showing the structure of Modification Example 1.

[0050] Fig. 9B It is a diagram showing the structure of Modification Example 2.

[0051] Fig. 9C It is a diagram showing the structure of Modification Example 3.

[0052] Fig.9D It is a diagram showing the structure of Modification Example 4.

[0053] Fig.9E It is a diagram showing the structure of Modification Example 4.

[0054] Fig.9F It is a diagram showing the structure of Modification Example 4.

[0055] Figure 9G It is a diagram showing the structure of Modification Example 5.

[0056] Figure 9H It is a diagram showing the structure of Modification Example 5.

[0057] Fig.10 This is a perspective view showing a cooling atom generating device according to a second embodiment.

[0058] Fig.11 This is a diagram when the permanent magnet according to the second embodiment is viewed from the Y direction.

[0059] Fig.12 It is a diagram showing the distribution of the magnetic field formed in the Y direction in the second embodiment.

[0060] Fig.13 It is a diagram showing the distribution of the magnetic field and the distribution of the magnetic field gradient.

[0061] Fig.14 This is a perspective view showing a cooling atom generating device according to a sixth modification.

[0062] Fig.15 This is a diagram showing the structure of Modification Example 7.

[0063] Fig.16 This is a diagram showing a cooling atom generating device.

[0064] Fig.17 This is a diagram showing a cooling atom generating device according to Modification Example 8.

[0065] Fig.18 This is a diagram showing a cooling atom generating device according to modification example 9.

[0066] Fig.19 It is a block diagram showing the overall structure of an optical lattice clock. DETAILED DESCRIPTION

[0067] The cooling atom generation device and cooling atom generation method of the embodiment are described. The cooling atom generation device of the embodiment is a device that continuously cools atoms and supplies them to a subsequent device. First, the principle of the embodiment is described, and then the device that embodies the principle is described.

[0068] The continuous measurement generally includes the first step, the second step and the third step, and each step is performed in the order of the first step, the second step and the third step. The first step is a step of generating atomic gas from solid atoms. The third step is a step of measuring physical quantities using cooled atomic gas. For example, in the third step, physical quantities are measured by atomic clocks, atomic interferometers or other quantum measurement devices. To give specific examples, the longitudinal Ramsey spectrometer (Hidetoshi Katori, "Longitudinal Ramsey spectroscopy of atoms for continuous operation of optical clocks", Applied Physics Express 14,072006 (2021)), optical lattice clocks (Japanese Patent No. 6206973) and atomic chips used in quantum measurement equipment are devices used in the third step. Of course, the devices used in the third step are not limited to these. Hereinafter, the device used in the third step will be referred to as a "latter-stage device."

[0069] The second step is an intermediate step between the first step and the second step, and includes a cooling step of cooling the atomic gas generated in the first step to a level that can be processed in the third step and a step of guiding the cooled atoms to a subsequent device.

[0070] In devices such as atomic clocks and atomic interferometers, in order to reduce the influence of Doppler shift generated during observation, it is necessary to cool the atomic gas to an extremely low temperature. This process is the above-mentioned cooling process. On the other hand, in order to suppress the spatial diffusion of the cooled atoms, a process of capturing atoms in space is required. In order to continuously supply the cooled atomic gas to the subsequent device, it is necessary to promote the movement of the atomic gas by applying an external force to the cooled atomic gas and guide the atomic gas to the subsequent device.

[0071] For example, as an external force that can promote the meaningful movement of neutral atoms belonging to alkaline earth metals, gravity (an external force that is effective when the mass of atoms is finite), magnetic force (an external force that is effective when the magnetic moment of atoms is finite), or laser radiation pressure (for example, laser radiation pressure used for laser deceleration, magneto-optical trap (MOT), or moving molasses) can be considered. Here, gravity and magnetic force are explained.

[0072] The ground state of alkaline earth metal atoms with two electrons in the outermost shell is a singlet spin state, and the angular momentum is zero. In this case, it may be considered difficult to use magnetic force as an external force to promote the movement of atomic gas. However, it is known that optical pumping (optical pump) generated during laser cooling can generate 3 Atoms in the P2 spin triplet state. Hereinafter, the method is described using strontium atoms as an example, but the method can also be applied to magnesium atoms, calcium atoms, and ytterbium atoms.

[0073] Figure 1 The energy levels of strontium atoms are shown in Figure 2. According to the research using strontium atoms (Masami Yasuda and Hidetoshi Katori, "Lifetime Measurement of the 3P2 Metastable State of Strontium Atoms", Phys. Rev. Lett. 92, 153004-Published 15 April 2004), 3 The lifetime of atoms in the P2 state is long enough. According to research using strontium atoms (SB Nagel, CE Simen, S. Laha, P. Gupta, V S Ashoka, and T C Billian, "Magnetic trapping of metastable 3P2 atomic strontium", PHYSICAL REVIEW A 67, 011401, 2003.), it is known that atoms can be trapped by magnetic force. Therefore, it is possible to make the lifetime of atoms in the metastable state long by gravity and magnetism. 3 Atomic movement in the P2 state.

[0074] In order to guide the atomic gas to the subsequent device, increase the 3 The number of atoms in the P2 state, 3 Cooling of atoms in the P2 state is effective.

[0075] As an increase 3 The method of determining the number of atoms in the P2 state can be exemplified by performing a method using an energy difference corresponding to a wavelength of 461 nm.1 S0- 1 The magneto-optical trap between P1 and the relaxation transition to 3 The atoms in the P2 state use the energy difference equivalent to the wavelength of 496nm. 3 P2- 3 The magneto-optical trap method for excitation between D3.

[0076] In addition, in order to 3 The atoms in the P2 state are further cooled to be efficiently measured in the third step, and it is considered that the energy difference using the wavelength equivalent to 2.9 μm is performed. 3 P2- 3 Doppler cooling of the excitation between D3. The transition line width is extremely narrow, at 57kHz, so a low cooling arrival temperature of several microkelvins can be achieved (Tomoya Akatsuka, Koji Hashiguchi, Tadahiro Takahashi, Noriaki Ohmae, Masao Takamoto and Hidetoshi Katori, "Three-stage laser cooling of Sr atoms using the 5s5p 3P2metastable state below Doppler temperatures", PHYSICAL REVIEW A 103, 023331 (2001).). The cooling arrival temperature is expressed as the Doppler temperature by the following formula (1).

[0077] [Mathematical formula 1]

[0078]

[0079] γ is the transition linewidth. is Planck's constant.

[0080] Hereinafter, specific techniques (first embodiment and second embodiment) for continuously generating cooled atomic gas and continuously guiding the atomic gas to a subsequent device will be described using alkaline earth metal atoms as an example.

[0081] Figure 2 The cooling atom generation method according to the first embodiment is shown.

[0082] In the first embodiment, the following steps A0 to A7 are performed.

[0083] A0: Preparation of solid samples of alkaline earth metal atoms

[0084] A1: Generate atomic gas from solid sample using atomic oven

[0085] A2: For 1 Atoms in the S0 state are cooled by a Zeeman slower atomic gas.

[0086] A3: For 1 Magneto-optical trapping (MOT) of atoms in the S0 state using a quasi-three-dimensional quadrupole magnetic field

[0087] A4: For 3 Magnetic trapping of atoms in the P2 state using a quasi-three-dimensional quadrupole magnetic field

[0088] A5: Make 3 The atoms in the P2 state move to a position where the magnetic force is balanced with the gravity or radiation pressure.

[0089] A6: Yes 3 Narrow linewidth cooling of atoms in the P2 state

[0090] A7: Optically pump the cooled atoms into a third state that is insensitive to magnetic fields, and guide the cooled atoms to the subsequent device using a moving optical lattice or an optical dipole guide.

[0091] Figure 3 A cooling atom generation method according to a second embodiment is shown.

[0092] In the second embodiment, the following steps B0 to B7 are performed.

[0093] B0: Preparation of solid samples of alkaline earth metal atoms

[0094] B1: Generating atomic gas from solid sample by atomic furnace

[0095] B2: Cooling of atomic gas by Zeeman slowdown

[0096] B3: Magneto-optical trap (MOT) using a two-dimensional quadrupole magnetic field

[0097] B4: Through gravity or radiation pressure 3 Atoms in the P2 state move on a magnetic guide

[0098] B5: Targeting 3 Ioffe-Pritchard magnetic trap of atoms in P2 state

[0099] B6: Yes 3 Narrow linewidth cooling of atoms in the P2 state

[0100] B7: Optically pump the cooled atoms into a third state that is insensitive to magnetic fields, and guide the cooled atoms to the downstream device by moving the optical lattice or optical dipole guide.

[0101] <Principle of the First Embodiment>

[0102] Below, strontium atoms ( 88 Sr) is used as an example to illustrate the principle of the first embodiment. Here, a three-dimensional coordinate system {X, Y, Z} is defined. The X axis, Y axis, and Z axis are mutually orthogonal axes. In other even-numbered isotopes (e.g., 86 Sr) or an odd-numbered isotope with a nuclear spin ( 87 The same operation can be performed in Sr).

[0103] The quasi-three-dimensional quadrupole magnetic field shown in A3 has a magnetic field distribution in which the magnetic field gradient in one axial direction is weaker than the magnetic field gradients in the other two axial directions.

[0104] The quasi-three-dimensional quadrupole magnetic field has

[0105]

[0106] (a aniso =|G Y -G X | / |G Z |~1,|G Y |<<|G X |<|G Z |)

[0107] Represents the magnetic field distribution.

[0108] {G X , G Y , G z} represents the magnetic field gradient around the zero magnetic field position. In the above example, the magnetic field gradient in the Y-axis direction is smaller than the magnetic field gradient in the X-axis and Z-axis directions. Weaker than the magnetic force in the X and Z axis directions.

[0109] In A3, the quasi-three-dimensional quadrupole magnetic field is combined with 1 S0- 1 The atoms are trapped near the origin, which is the zero magnetic field position, by the interaction of the 461nm laser light resonating in the P1 state. 1 P1 state passes 1 D2 state relaxes to 3 The process of optical pumping of the P2 state generates a metastable 3 Atoms in P2 state.

[0110] In A4, for 3The magnetic quantum number m in the atom in the P2 state J For atoms with a value of 1 or 2, the weak magnetic field is energetically stable and they are magnetically trapped near the zero magnetic field position of the quasi-three-dimensional quadrupole magnetic field. The magnetic interaction potential U between an atom and a quasi-three-dimensional quadrupole magnetic field is mag Near the zero magnetic field position, it is expressed by the following equation (2).

[0111] [Mathematical formula 2]

[0112]

[0113] g is the g factor (in the state of the atom 3 In the case of P2 state, g=3 / 2), μ B It is the Bohr magneton.

[0114] In addition, the magnetic force F acting on the atom mag It is represented by the following formula (3).

[0115] [Mathematical formula 3]

[0116]

[0117] In A5, gravity acts on the atom in the -Y direction (F = mg0). Here, m is the mass of the atom and g0 is the acceleration due to gravity. mag When the Y component of is large, the atoms will move from the zero magnetic field position to the -Y direction (that is, the direction of gravity) due to gravity.

[0118] In A5, the radiation pressure of the second light (F Rad ) acts on the atom in the Y direction. When the radiation pressure is greater than the F at the zero magnetic field position mag When the Y component is large, the atoms will move from the zero magnetic field position to the -Y direction (that is, the direction of travel of the second light) due to radiation pressure.

[0119] In A6, by irradiating 3 P2- 3 The 2.9μm laser that resonates between the D3 states performs Doppler cooling. The cooled atoms are in the F mag The Y component, gravity mg, and radiation pressure (F Rad )The equilibrium position is captured.

[0120] In A7, the position where the atoms in A6 are captured is connected to the input part of the subsequent device (the part where the cooling atoms are input) by an optical dipole guide, and the cooling atoms are optically pumped to a third state that is insensitive to the magnetic field, so that the cooling atoms can be guided to the subsequent device. For example, the cooling atoms can be moved from the captured position to the input part of the subsequent device by using the mobile optical lattice technology (Japanese Patent Publication No. 2019-129166). The third state can also be the magnetic quantum number m J =0 3 P2 status, 3 P0 state or 1 S0 state.

[0121] The atoms used as samples are in the magnetic quantum number m J =2 state 88 In the case of Sr atoms, the gravitational acceleration g0 is 9.8 m / s 2 The magnetic force that balances gravity can be obtained by a magnetic field with a magnetic field gradient of 5.2G / cm. That is, in order to move atoms from the zero magnetic field center to the trapped position (the position where gravity, magnetic force and the radiation pressure of the second light are balanced) on the Y axis by gravity, the magnetic field gradient from the zero magnetic field center to the trapped position needs to be less than 5.2G / cm. On the other hand, in order to move atoms by magneto-optical trap 1 The atoms in the S0 state are sufficiently cooled to 3 The atoms in the P2 state are magnetically trapped, preferably with a magnetic field gradient of 30 to 100 G / cm. A quasi-three-dimensional quadrupole magnetic field with strong anisotropy can meet these conditions.

[0122] A quasi-three-dimensional quadrupole magnetic field with strong anisotropy can be realized by, for example, a combination of a rod-shaped permanent magnet and a coil. The magnetization direction of the permanent magnet is the direction from the permanent magnet to the coil. When defining the height H (magnetization direction), width W, and length L of the permanent magnet, a permanent magnet having a relationship of L>>H, W is used. As an example, L=50mm, W=H=2mm, and these values ​​are just examples.

[0123] A highly anisotropic quadrupole magnetic field is realized by, for example, a combination of a rod-shaped permanent magnet and a ring magnet.

[0124] Since the permanent magnet or coil is arranged in the area where the magneto-optical trap is realized, it is arranged in a manner that does not interfere with the laser light (specifically, the laser light irradiated from six directions) used to realize the magneto-optical trap. For example, in the case of a rod-shaped permanent magnet, a ring-shaped coil or a ring-shaped permanent magnet having a hole formed therein for passing the laser light is used.

[0125] <Principle of the Second Embodiment>

[0126] Below, strontium atoms ( 88 Sr) is used as an example to explain the principle of the second embodiment. 87 Sr) can also perform the same operation.

[0127] In B2, the magnetic field distribution and the laser apply radiation pressure to the atomic gas emitted from the nuclear reactor in the Y-axis direction, so that the atoms are decelerated and cooled.

[0128] In B3 to B5, first, the atoms enter a two-dimensional quadrupole magnetic field.

[0129]

[0130] (G is a constant) and the leakage magnetic field of the Zeeman magnetic field, the Y component magnetic field generated by the stop coil, etc.

[0131] f(y) decreases monotonically from the Zeeman deceleration region of B2 to the position where the atom is captured by the magnetic trap in B5, becomes minimum at the capture position, and increases at a position further ahead of it.

[0132] In B3, through the two-dimensional quadrupole magnetic field and 1 S0- 1 The interaction of the 461nm laser light resonating between the P1 states causes the atoms to be decelerated and cooled by the restoring force, and to be strongly confined to the central axis of the atomic beam (Y axis). The laser light is irradiated in the X and Z directions in a manner that is opposite to each other. The laser light can also be irradiated in the Y direction so that the atoms are also subjected to radiation pressure in the Y direction due to the sticking effect.

[0133] Generated from 1 P1 status passes 1 D2 state relaxes to 3 Atoms in the P2 state. 3 The magnetic quantum number m in the atom in the P2 state J The atoms with 1 or 2 are gathered by the magnetic force near the zero magnetic field position through the two-dimensional quadrupole magnetic field. The magnetic interaction potential U between the atoms and the two-dimensional quadrupole magnetic field is proportional to |B|. In addition, the magnetic force F acting on the atoms mag It is represented by the following formula (4).

[0134] [Formula 4]

[0135]

[0136] In B3 to B5, a strong magnetic force is applied in the radial direction (X and Z directions) to constrain the atoms on the central axis of the atomic beam. By applying a weak bias magnetic field on the Y axis, the Majorana flip is suppressed, and a weak confinement on the Y axis is performed by magnetic force. Magnetic quantum number m J Atoms with a value of 1 or 2 have the property of liking weak magnetic fields, and are therefore guided in the Y direction by the magnetic force and move to a position with a very small magnetic field.

[0137] In B6, the atoms are trapped at the position where they are illuminated. 3 P2- 3 The atoms are Doppler cooled by a 2.9μm laser beam that resonates in the D3 state. After Doppler cooling, the atoms are trapped at a position where the magnetic force, the radiation pressure of the laser beam, and gravity are balanced.

[0138] In B7, by connecting the position where the atoms are trapped in B6 to the input of the subsequent device through an optical dipole guide, the cooled atoms are optically pumped to a third state that is insensitive to the magnetic field, and the cooled atoms can be guided to the subsequent device. As another example, the cooled atoms can be moved from the trapped position to the input of the subsequent device by using a moving optical lattice technique. The third state can also be a magnetic quantum number m J =0 3 P2 status, 3 P0 state or 1 S0 state.

[0139] In the first embodiment and the second embodiment, the magnetic quantum number m is used. J Atoms with a value of 1 or 2 prefer weak magnetic fields, and this technology guides the atoms to the position where the magnetic field is minimum.

[0140] Typically, when atoms move to a position of zero magnetic field, the quantum state is destroyed due to spin flipping. In the first embodiment, the position where the atoms are finally captured is the position where the magnetic force, gravity and the radiation pressure of the second light are balanced, so the magnetic field at this position is not zero. In the second embodiment, atoms are always processed in a region where there is a finite magnetic field called f(y). In this way, the systems of the first and second embodiments are systems to which a bias magnetic field B0 is applied, thereby avoiding the destruction of the quantum state caused by spin flipping. Moreover, when laser cooling is performed, it is desirable to avoid spin flips caused by transitions to unpreferred spin states due to non-resonant excitation of the cooling light. This condition is to make the Zeeman frequency shift of the cooling transition caused by the bias magnetic field B0 so as to excite σ + The incident laser cooling light is relative to the π transition or σ transition. - The transition is fully non-resonant. If the Bohr magneton is set to μB , let the Lande's g factor of the upper energy level of the laser cooling transition be g', and let the spectral width of the laser cooling transition be γ, then the magnitude that the bias magnetic field B0 should satisfy is expressed by the following equation (5).

[0141] [Formula 5]

[0142]

[0143] In the first and second embodiments, for example, permanent magnets are used. Since permanent magnets do not require switching of magnetic fields, they are more suitable as magnetic field generation sources than coils in systems that require a stable magnetic field at all times.

[0144] On the other hand, an environment in which a device susceptible to adverse effects of magnetic noise is adjacent to a magnetic field generating source is envisioned. In such an environment, for example, a permanent magnet of as small a size as possible is used. As another example, an integrated magnetic field generating source is used in a configuration for forming a quadrupole magnetic field. As yet another example, a configuration is used in which a magnetic field is sealed by a high-permeability yoke, a shield, etc. (e.g., a member made of a permalloy material, etc.) so that it does not leak.

[0145] The configuration and steps (steps A0 to A7 ) of the first embodiment may be combined with the configuration and steps (steps B0 to B7 ) of the second embodiment.

[0146] In the first embodiment, a quasi-three-dimensional quadrupole magnetic field is generated by a rod-shaped permanent magnet or the like, and in the second embodiment, an additional magnetic field in the Y direction is generated by a stop coil or the like. For example, the quasi-three-dimensional quadrupole magnetic field of the first embodiment and the additional magnetic field of the second embodiment may be combined. After executing steps A0 to A3, 3 The atoms optically pumped in the P2 state are magnetically trapped by the quasi-three-dimensional quadrupole magnetic field and the additional magnetic field in the Y direction, and move to a position where the magnetic force acting in the Y direction is balanced with the gravity or radiation pressure. Then, by executing steps B6 and B7, the cooled atoms are guided to the subsequent device by the moving optical lattice or the optical dipole guide.

[0147] For example, the magnetic field of the second embodiment (that is, the two-dimensional quadrupole magnetic field (G{X, 0, -Z}) and the Y component magnetic field ({0, f(Y), 0}) generated by the stop coil, etc.) is added to the quasi-three-dimensional quadrupole magnetic field ({XG X , YG Y , ZG Z},|G Y |<<|G X |<|G Z |) after the magnetic field ({X(G+G X ), f(Y)+YGY , Z(G+G Z Specifically, the magnetic field ({X(G+G X ), f(Y)+YG Y , Z(G+G Z )}) can also be used for 1 Magneto-optical trapping of atoms in the S0 state, 3 Magnetic trapping of atoms in the P2 state and 3 Guiding atoms in the P2 state. By appropriately selecting the magnitude of the magnetic field gradient and the spatial distribution of the Y component magnetic field, the position of the trap and the position of the transport destination can be finely adjusted, and the magnetic force used to converge the atoms can be appropriately adjusted and finely adjusted.

[0148] Hereinafter, the specific configuration of each embodiment will be described.

[0149] <Specific Configuration of First Embodiment>

[0150] Below, refer to Figures 4 to 7 The cooling atom generation device and the cooling atom generation method according to the first embodiment will be described. Figure 4 This is a perspective view showing the cooling atom generating device according to the first embodiment. Figure 5 It is a perspective view showing a magneto-optical trap device (MOT device). Figure 6 This is a diagram of the magneto-optical trap device viewed from the +Z direction. Figure 7 This is a diagram of the magneto-optical trap device viewed from the -Y direction. Define a three-dimensional coordinate system {X, Y, Z}. The X-axis, Y-axis, and Z-axis are mutually orthogonal axes. The X-direction is the direction in which the atomic beam emitted from the atomic reactor travels. The -Y direction is the direction in which gravity acts.

[0151] The cooling atom generation device 10 of the first embodiment includes an atomic furnace 12, a Zeeman slowdown device 14, and a magneto-optical trap device (MOT device) 16. The atomic furnace 12, the Zeeman slowdown device 14, and the magneto-optical trap device 16 are set in an ultra-high vacuum environment. In each figure, the illustration of the fixing parts of each module, the viewport for inputting and outputting lasers, the vacuum exhaust port, and the vacuum exhaust pump are omitted.

[0152] The atomic furnace 12 includes a sample container, a heater, a capillary nozzle, a thermometer, an electrical connector, and a thermal radiation shield. A sample is placed in the sample container. For example, strontium atoms ( 87 Sr. 88Sr) as a sample. By heating the sample in the sample container by a heater, atoms evaporate and atomic gas is generated. The capillary nozzle is connected to the sample container. The atomic gas is emitted as a directional atomic beam through the capillary nozzle. The thermometer is used to measure the temperature of the sample container. The electrical connector is used to supply power to the heater. The thermal radiation shielding member is used to shield the heat radiation from the heater and the sample container to the outside. As the atomic furnace 12, a well-known atomic furnace can be used. The atomic beam emitted from the atomic furnace 12 travels to the subsequent Zeeman reducer 14.

[0153] The Zeeman slowdown device 14 includes a bore and a magnetic field generating unit 14a disposed around the bore and extending in the X direction. The magnetic field generating unit 14a includes, for example, a solenoid coil and generates a magnetic field along the central axis (X axis) of the bore extending in the X direction. Here, as an example, the magnetic field generating unit 14a generates a magnetic field whose intensity decreases as it is farther from the atomic reactor 12. In addition, the resonant laser 14b is irradiated into the bore from the direction opposite to the traveling direction of the atomic beam (-X direction). The atomic beam emitted from the atomic reactor 12 is irradiated into the bore and travels in the X direction in the bore. The Zeeman slowdown device 14 uses the resonant laser 14b and the gradient magnetic field formed by the magnetic field generating unit 14a to decelerate the speed of the atomic beam having a large initial velocity emitted from the atomic reactor 12 to a speed that can be captured by the subsequent magneto-optical trap device 16 according to the Zeeman deceleration method. The high-temperature atomic beam travels toward the magneto-optical trap device 16 in the bore while being decelerated according to the Zeeman deceleration method. As the Zeeman reducer 14 , a well-known Zeeman reducer can be used.

[0154] The MOT device 16 includes a vacuum chamber, and a trapping space for trapping atoms is formed in the vacuum chamber. The atomic beam traveling from the Zeeman reducer 14 to the MOT device 16 is trapped by the MOT device 16. Specifically, the MOT device 16 includes a plurality of optical elements forming a laser group 18 and a magnetic field generator 22.

[0155] A plurality of optical elements, such as a light source, a mirror such as a λ / 4 mirror 20, and a beam splitter (beamsplitter), irradiate a laser group 18 to the zero magnetic field position from six directions for the purpose of providing the atoms with a restoring force due to radiation pressure. The laser group 18 includes a laser traveling in the X direction on the X axis, a laser traveling in the -X direction opposite thereto, a laser traveling in the Y direction on the Y axis, a laser traveling in the -Y direction opposite thereto, a laser traveling in the Z direction on the Z axis, and a laser traveling in the -Z direction opposite thereto. A λ / 4 mirror 20 is provided on the Z axis. The laser traveling in the -Z direction is formed by the laser traveling in the Z direction and the λ / 4 mirror 20. That is, the laser traveling in the Z direction is reflected by the λ / 4 mirror 20, thereby forming a laser traveling in the -Z direction.

[0156] The magnetic field generating unit 22 includes a coil 24 and a permanent magnet 26, and generates a quasi-three-dimensional quadrupole magnetic field. The permanent magnet 26 has a long and thin rod shape. The permanent magnet 26 is arranged along the Y direction and is magnetized in the Z direction. The coil 24 has an inner diameter that is the same as the length of the permanent magnet 26 (the length in the direction in which the permanent magnet 26 extends (that is, the length in the Y direction)). The coil 24 is arranged parallel to the XY plane formed by the X-axis and the Y-axis.

[0157] In addition, the light source of the irradiation laser beam group 18 and the magnetic field generating unit 22 correspond to an example of a first cooling unit.

[0158] The permanent magnet 26 , the λ / 4 mirror 20 , and the coil 24 are arranged in this order along the Z direction, and the zero magnetic field position is between the λ / 4 mirror 20 and the coil 24 .

[0159] A current is passed through the coil 24 in such a manner that the absolute value of the intensity of the magnetic field formed by the coil 24 at the center position of the capture space for realizing the magneto-optical trap is equal to the absolute value of the intensity of the magnetic field formed by the permanent magnet 26 at the center position, and the directions of these magnetic fields are opposite to each other. The capture space for realizing the magneto-optical trap corresponds to an example of the first region.

[0160] The λ / 4 mirror 20 is set at a position that does not block the laser light traveling in the X direction, the laser light traveling in the -X direction, the laser light traveling in the Y direction, and the laser light traveling in the -Y direction. In order to prevent the optical characteristics of the λ / 4 mirror 20 from being deteriorated, it may be fixed at a position other than the light receiving portion (e.g., four corners). In addition, the λ / 4 mirror 20 is set in a manner that does not directly contact the permanent magnet 26.

[0161] Laser 28 is a laser for narrow line width cooling irradiated from light source 29, and has a wavelength of 2.9 μm. Laser 28 is irradiated near position 30 where magnetic force, gravity, and radiation pressure of laser 28 are balanced. Position 30 is equivalent to an example of the second region, and light source 29 is equivalent to an example of the second cooling unit.

[0162] Reference Figure 8 To illustrate the trapped atoms and the magnetic field components in various directions. Figure 8 The calculation results of the trapped atoms and the magnetic field components in various directions are shown.

[0163] Figure 8 The λ / 4 mirror 20 is shown when viewed from the Z direction. As indicated by reference numeral 32, atoms are trapped above the λ / 4 mirror 20 on the Z axis. The space indicated by reference numeral 32 is a trapping space, which corresponds to the first region.

[0164] Figure 8 BX is the magnetic field component in the X direction on the X axis, B Y is the magnetic field component in the Y direction on the Y axis, B Z is the magnetic field component in the Z direction on the Z axis. In the coordinate graph showing the calculation results of each magnetic field component, the horizontal axis shows the position in each direction, and the vertical axis shows the intensity. X , B Y and B Z The zero magnetic field position is equivalent to the origin of the X-axis, Y-axis, and Z-axis. The atom is trapped in the trapping space (equivalent to the first region) including the zero magnetic field position. X is the magnetic field gradient in the X direction (the gradient of the magnetic field component in the X direction), G Y is the magnetic field gradient in the Y direction (the gradient of the magnetic field component in the Y direction), G Z is the magnetic field gradient in the Z direction (the gradient of the magnetic field component in the Z direction).

[0165] The following results were obtained from the calculation results of the magnetic field.

[0166] G Z =100G / cm

[0167] -G Y <<-G X ~G Z

[0168] a aniso =0.96

[0169] The distribution of the generated magnetic field can be evaluated as a quasi-three-dimensional quadrupole magnetic field distribution with anisotropy. That is, although strong magnetic forces are generated in the X and Z directions, weak magnetic forces are generated in the Y direction under the action of gravity. It can be said that the distribution of the magnetic field is a quasi-three-dimensional quadrupole magnetic field distribution. Here, as -G Y <<-G X ~G Z In the example, Gz to -Gx = 100 G / cm is exemplified, but the range of 30 to 100 G / cm is preferred.

[0170] The quasi-three-dimensional quadrupole magnetic field and the frequency-adjusted laser beam 18 interact with the low-speed atomic beam emitted from the Zeeman slowdown device 14, so that atoms are trapped by magneto-optics in a trapping space including a zero magnetic field position.

[0171] The relaxation of atoms trapped in the trapping space by magneto-optical trapping generates 3 Atoms in P2 state.

[0172] In 3 The atoms in the P2 state are subjected to a strong magnetic force by interacting with the quasi-three-dimensional quadrupole magnetic field, and are magnetically trapped by this magnetic force. Figure 8 As shown in the figure, although strong magnetic forces are generated in the X and Z directions, a weak magnetic force is generated in the Y direction due to gravity. 3 The magnetic quantum number m in the P2 state J For 2 88 The gravity of Sr atoms is equivalent to the magnetic force obtained by the magnetic field gradient of 5.2G / cm. On the other hand, the magnetic field gradient in the Y direction at the zero magnetic field position is about 2G / cm. Therefore, the magnetic force obtained by the magnetic field gradient in the Y direction is smaller than the gravity. Therefore, the gravity is stronger than the magnetic force in the Y direction. 3 The magnetic quantum number m in the P2 state J For 2 88 The Sr atomic cloud is moved in the −Y direction to a position where the magnetic force, gravity, and radiation pressure of the laser light 28 (second light) in the Y direction are balanced.

[0173] Figure 8 A coordinate diagram of the magnetic force Fy in the Y direction is shown. The horizontal axis shows the position in the Y direction, and the vertical axis shows the magnitude of the magnetic force. Gravity is also shown in the coordinate diagram. In the coordinate diagram, the point indicated by the reference numeral 34 is the point where the value of the magnetic force in the Y direction intersects with the value of the gravity, and the intersection point corresponds to the position 30 where the magnetic force in the Y direction, gravity, and the radiation pressure of the laser 28 (second light) are balanced. Figure 8 In the example shown, position 30 is a position 7.5 mm away from the zero magnetic field position in the -Y direction. That is, the atom is moved 7.5 mm in the -Y direction from the position where the atom is trapped.

[0174] Move to position 30 88 The Sr atomic cloud is Doppler cooled by the interaction with the laser light 28 (laser light with a wavelength of 2.9 μm) irradiated to the position 30. 88 The temperature of the Sr atomic cloud dropped to a few microkelvins.

[0175] Fig. 9A , 9B , 9C, 9D, 9E, 9F, 9G, and 9H show modified examples of the first embodiment.

[0176] exist Fig. 9A In the first modification shown, the compensation coil 36 is disposed between the Zeeman slowdown device 14 and the coil 24 so that the leakage magnetic field from the Zeeman slowdown device 14 does not disturb the distribution of the quasi-three-dimensional quadrupole magnetic field. For example, the compensation coil 36 is disposed around the opening of the Zeeman slowdown device 14 from which the atomic beam emerges.

[0177] exist Fig. 9BIn the second modification shown, the magnetic field generating unit 14a, the adjustment coil 38 and the permanent magnet 26 are arranged in this order. As a result, the distribution of the quasi-three-dimensional quadrupole magnetic field becomes a distribution from the symmetry axis of the Zeeman magnetic field to the reference. Figure 4 , Fig. 9A The distribution of the quasi-three-dimensional quadrupole magnetic field formed by the structure shown in the figure is rotated 90 degrees. In this structure, the quasi-three-dimensional quadrupole magnetic field is formed by the magnetic field generated by the permanent magnet 26 and the magnetic field formed by the magnetic field generating unit 14a and the adjustment coil 38. By utilizing the leakage magnetic field from the magnetic field generating unit 14a, Fig. 9A The structure shown saves power compared to the structure shown. It is necessary to make the resonant laser for the Zeeman deceleration method and the laser for the magneto-optical trap be incident from the reactor side to the magneto-optical trap device side along the central axis of the Zeeman decelerator. This method is described in Japanese Patent Publication No. 2021-163884, etc.

[0178] Fig. 9C The configuration of Modification Example 3 is shown. Figure 4 , 9A In the configuration shown in FIG. 9B , the magnetic field generating portion 14a of the Zeeman reducer 14 is a decreasing field type magnetic field generator, which generates a magnetic field whose intensity decreases as it is farther from the nuclear reactor 12. The magnetic field generating portion 14a of the Zeeman reducer 14 of the modification 3 is an increasing field type magnetic field generator, which generates a magnetic field whose intensity increases as it is farther from the nuclear reactor 12. Since the leakage magnetic field from the magnetic field generating portion 14a is large, a quasi-three-dimensional quadrupole magnetic field can be formed by the leakage magnetic field and the magnetic field generated by the permanent magnet 26. In this case, an adjustment coil 38 can also be used to supplement the insufficient magnetic field or perform fine adjustment.

[0179] Figure 9D to Figure 9F The configuration of Modification 4 is shown. Fig.9D and Fig.9F This is a diagram when the structure of Modification Example 4 is viewed from the direction in which gravity acts. Fig.9E This is a diagram showing the configuration of Modification Example 4 when viewed from a direction perpendicular to the direction in which gravity acts. Fig.9D and Fig.9E In , the magnetic flux is represented by arrows. Fig.9E In FIG. 1 , the laser 28 for narrow line width cooling is indicated by an arrow. Fig. 9B In the configuration shown (configuration of variant 2), the direction in which the weak magnetic force is generated is the direction in which gravity acts. Figure 9D to Figure 9F In the structure shown, the direction of the weak magnetic force is orthogonal to the direction of gravity. As a result, the distribution of the quasi-three-dimensional quadrupole magnetic field becomes a distribution after rotating 90° from the distribution of the quasi-three-dimensional quadrupole magnetic field formed by the structure of Modification Example 2 based on the symmetry axis of the Zeeman magnetic field.

[0180] In the capture space (space indicated by reference numeral 32) corresponding to the first region, atoms are captured by a magneto-optical trap. The captured atoms are subjected to narrow-linewidth cooling by the laser 28 for narrow-linewidth cooling. In addition, at position 30, which is further away from the position of the capture space, the radiation pressure of the laser 28 is balanced with the weak magnetic force described above. As a result, the atoms move to position 30 corresponding to the second region. Figure 4 In the configuration shown, gravity or a part of gravity acts in addition to magnetic force to move atoms from the first region to the second region. On the other hand, in the configuration of Modification 4, the radiation pressure of the narrow linewidth cooling laser 28 acts in addition to magnetic force.

[0181] Figure 9G and Figure 9H The configuration of Modification 5 is shown. Figure 9G This is a diagram when the structure of Modification Example 5 is viewed from the direction in which gravity acts. Figure 9H This is a diagram when the structure of modification example 5 is viewed from a direction orthogonal to the direction in which gravity acts. The structure of modification example 5 includes a λ / 4 mirror 90 and a light shielding wall 94 surrounding a clock transition space 92 equivalent to the subsequent stage. The light shielding wall 94 is an example of a blocking mechanism. An opening 94a is formed in the light shielding wall 94. In addition, a first area (a space indicated by the reference numeral 32) and a second area (a space indicated by the reference numeral 30) are formed. The first area is spatially separated from the clock transition space 92. As an example, a first moving direction from the first area to the second area and a second moving direction from the second area to the clock transition space 92 are orthogonal to each other.

[0182] In the first region, atoms are trapped by a magneto-optical trap. The atoms trapped by the magneto-optical trap relax to 3 The P2 state is captured by the magnetic guide formed by the rod-shaped permanent magnet 26. 3 The atoms in the P2 state are moved to the second region where the radiation pressure is balanced with the weak magnetic force described above by the radiation pressure of the laser 28 for narrow linewidth cooling, and are narrow linewidth cooled. In the second region, the cooled atoms are optically pumped to the third state that is insensitive to the magnetic field, and are guided to the clock transition space 92 of the subsequent stage by the moving optical lattice 96 that connects the second region to the clock transition space 92. An opening 94a is formed in the light shielding wall 94, and the cooled atoms are guided to the clock transition space 92 through the opening 94a.

[0183] For example, in the third state 1 In the S0 state, the laser light irradiated to the first region and the spontaneous emission light generated in the magneto-optical trap may act on the cooled atoms in the third state to cause an optical frequency shift, which may adversely affect the measurement in the subsequent stage.

[0184] On the other hand, Figure 9HIn the structure shown, the clock transition space 92 is covered by the light shielding wall 94 having light shielding properties, so that light directly leaking from the first area into the clock transition space 92 or light leaking from the first area into the clock transition space 92 through the opening 94a is sufficiently suppressed. This can suppress the influence on the subsequent stage.

[0185] exist Figure 9H In the example shown, as an example, the first moving direction from the first area to the second area and the second moving direction from the second area to the clock transition space 92 are orthogonal to each other, but this is just an example, as long as the angle between the first moving direction and the second moving direction is non-zero. In other words, it is sufficient to form the first area, the second area, and the clock transition space 92 in such a way that the straight line connecting the first area and the second area and the straight line connecting the second area and the clock transition space 92 are not arranged on the same straight line. By setting the angle between the first moving direction and the second moving direction to be non-zero, it is possible to suppress the naturally emitted light from the first area from entering the clock transition space 92 through the opening 94a and the like. Therefore, the angle between the first moving direction and the second moving direction is not limited to 90°, as long as it is a non-zero angle.

[0186] Fig.16 Shown with Figure 9G and Figure 9H The same structure as shown. Fig.16 In the cooling atom generating device shown, laser light 28 corresponding to the second light and a moving optical lattice 96 (or an optical dipole guide) are used. In addition, a clock transition space 92 is formed as a subsequent structure, and a first region (a space indicated by reference numeral 32) and a second region (a space indicated by reference numeral 30) are formed. The first region and the clock transition space 92 are spatially separated. As an example, a first moving direction from the first region to the second region and a second moving direction from the second region to the clock transition space 92 are orthogonal to each other. According to this structure, the clock transition space 92 is sufficiently blocked from the first region, so that the naturally emitted light generated in the first region can be prevented from entering the clock transition space 92.

[0187] exist Fig.16In the example shown, as an example, the first moving direction and the second moving direction from the second area to the clock transition space 92 are orthogonal to each other, but this is just an example, as long as the angle between the first moving direction and the second moving direction is non-zero. In other words, it is sufficient to form the first area, the second area, and the clock transition space 92 in such a way that the straight line connecting the first area and the second area and the straight line connecting the second area and the clock transition space 92 are not arranged on the same straight line. By setting the angle between the first moving direction and the second moving direction to be non-zero, it is possible to suppress the naturally emitted light from the first area from entering the clock transition space 92. Therefore, the angle between the first moving direction and the second moving direction is not limited to 90°, as long as it is a non-zero angle.

[0188] <Specific Configuration of Second Embodiment>

[0189] Below, refer to Figures 10 to 13 A cooling atom generation device and a cooling atom generation method according to the second embodiment will be described. Fig.10 This is a perspective view showing a cooling atom generating device according to a second embodiment. Fig.11 This is a diagram of four permanent magnets viewed from the Y direction. Fig.12 It is a diagram showing the distribution of the magnetic field formed in the Y direction. Fig.12 The cooling atom generating device according to the second embodiment is also shown when viewed from the Z direction. Fig.13 It is a diagram showing the distribution of the magnetic field and the distribution of the magnetic field gradient. A three-dimensional coordinate system {X, Y, Z} is defined. The X axis, Y axis, and Z axis are mutually orthogonal axes. The Y direction is the direction in which the atomic beam emitted from the nuclear reactor travels.

[0190] The cooling atom generating device 50 of the second embodiment includes an atomic furnace 52, a Zeeman reducer 54, and a magneto-optical trap device 56. The atomic furnace 52, the Zeeman reducer 54, and the magneto-optical trap device 56 are arranged in an ultra-high vacuum environment. In each figure, the fixtures of each module, the viewport for inputting and outputting lasers, the vacuum exhaust port, and the vacuum exhaust pump are omitted. In addition, as in the first embodiment, strontium atoms ( 87 Sr or 88 Sr) as the sample.

[0191] The atomic furnace 52 has the same structure as the atomic furnace 12 of the first embodiment, and emits an atomic beam by heating the sample with a heater. The Zeeman slowdown device 54 has the same structure as the Zeeman slowdown device 14 of the first embodiment. Specifically, the Zeeman slowdown device 54 has a magnetic field generating unit 54a, and the speed of the atomic beam is slowed down by the magnetic field formed by the magnetic field generating unit 54a and the laser 54b.

[0192] The atomic beam emitted from the atomic reactor 52 is decelerated by the Zeeman decelerator 54 and travels to the magneto-optical trap device 56. In the magneto-optical trap device 56, atoms are trapped by a magneto-optical trap using a two-dimensional quadrupole magnetic field. Specifically, the magneto-optical trap device 56 includes a plurality of optical elements forming a laser group 58 and a magnetic field generator 60.

[0193] Multiple optical elements, such as light sources, mirrors, and beam splitters, are used to irradiate the zero magnetic field position with a laser beam group 58 from four directions in order to provide restoring force to the atoms due to radiation pressure. Fig.10 In the example shown, the laser group 58 includes a laser beam traveling in the X direction on the X axis, a laser beam traveling in the opposite -X direction, a laser beam traveling in the Z direction on the Z axis, and a laser beam traveling in the opposite -Z direction. The laser beam 54b for Zeeman deceleration travels in the -Y direction.

[0194] The magnetic field generating unit 60 generates a two-dimensional quadrupole magnetic field including four permanent magnets 62. Each permanent magnet 62 has a long and thin bar shape and is arranged along the Y direction at intervals of 90 degrees around the Y axis with the Y axis as the center.

[0195] Fig.11 The permanent magnets 62 are shown when viewed from the Y direction. Fig.11 Magnetic fluxes formed by the permanent magnets 62 are shown. The permanent magnets 62 are magnetized in the height direction H. Reference numeral 62a indicates a positive pole, and reference numeral 62b indicates a negative pole. The permanent magnets 62 are arranged so that their magnetic poles are opposite to each other. The laser beams included in the laser group 58 pass through between the permanent magnets 62.

[0196] A two-dimensional quadrupole magnetic field (B=G(x, 0, -z), G=174 G / cm) distributed in the X direction and the Z direction is formed by the four permanent magnets 62 .

[0197] In addition, a stop coil 64 is provided. The stop coil 64 is a coil surrounding the Y axis (equivalent to the axis of the atomic beam) with the Y axis as the center, and is provided at a position opposite to the Zeeman reducer 54 with four permanent magnets 62 interposed therebetween. The magnetic field generating section 54a (that is, the Zeeman coil) of the Zeeman reducer 54 and the stop coil 64 generate a magnetic field in the Y direction.

[0198] In addition, the light source for irradiating the laser beam group 58, the magnetic field generating unit 60, and the stop coil 64 correspond to an example of a first cooling unit.

[0199] Generated by relaxation from a cloud of atoms trapped in a 2D magneto-optical trap using a 2D quadrupole magnetic field 3 Atoms in the P2 state. The trapping space for realizing a magneto-optical trap using a two-dimensional quadrupole magnetic field corresponds to an example of the first region.

[0200] exist 3 The magnetic quantum number m in the P2 state J 1 or 2 88 Sr atoms have the property of liking weak magnetic fields. In a two-dimensional quadrupole magnetic field, they are strongly bound to the Y axis due to the magnetic forces in the X direction and the Z direction.

[0201] Regarding this, see Fig.13 Provide explanation. Fig.13 B X is the magnetic field component in the X direction on the X axis, B Z is the magnetic field component in the Z direction on the Z axis. dB X / dX is the magnetic field gradient in the X direction (the gradient of the magnetic field component in the X direction), dB Z / dZ is the magnetic field gradient in the Z direction (the gradient of the magnetic field distribution in the Z direction). The horizontal axis of each graph shows the position in the X direction or the Z direction.

[0202] At the position corresponding to the origin of the X-axis, Y-axis, and Z-axis, the magnetic field component in the X direction and the magnetic field component in the Z direction are each zero, and the absolute values ​​of the magnetic field gradient in the X direction and the magnetic field gradient in the Z direction at this position become larger. For example, the magnetic field gradient in the X direction becomes -174G / cm, and the magnetic field gradient in the Z direction becomes 174G / cm. In this way, at the position where the magnetic field component in the X direction and the magnetic field component in the Z direction are each zero, the magnetic force in the X direction and the magnetic force in the Z direction become stronger, and are strongly bound to the Y axis.

[0203] Fig.12 The magnetic field component B in the Y direction is shown Y . B Y The potential decreases monotonically from the exit of the Zeeman reducer 54 (that is, the position where the atomic beam is emitted from the magnetic field generating unit 54a) to the minimum position 66 near the stop coil 64. The minimum position 66 is the position where the effective potential becomes minimum. The effective potential refers to the combined potential of the magnetic force and the gravity acting on the atoms. Y The magnetic force proportional to the gradient of the absolute value of is guided from the position where the atomic cloud is captured (that is, the origin of the X-axis, the Y-axis, and the Z-axis) toward the minimum position 66. The minimum position 66 corresponds to an example of the second region.

[0204] Move to the minimum position 66 88 The Sr atomic cloud is Doppler cooled by the interaction with the laser light 68 (laser light with a wavelength of 2.9 μm) irradiated from the light source 69 to the minimum position 66. 88The temperature of the Sr atomic cloud drops to a few microkelvins. After Doppler cooling, the atoms are trapped at a position where the radiation pressure of the laser 68, the magnetic force, and the gravity are balanced. In addition, the light source 69 corresponds to an example of the second cooling unit.

[0205] Fig.14 and Fig.15 A modified example of the second embodiment is shown.

[0206] Fig.14 : is a perspective view showing a cooling atom generating device according to Modification 6. In Modification 6, in addition to the magneto-optical trap using a two-dimensional quadrupole magnetic field, radiation pressure is applied in the Y direction by the photocohesion effect.

[0207] The laser light 70 for applying radiation pressure in the Y direction is incident on the magneto-optical trap device 56 from the same port as the laser light 54b for the Zeeman deceleration method. Fig.14 In the example shown, two laser beams 70 are incident on the MOT device 56 along the laser beam 54b.

[0208] Two λ / 4 mirrors 72 are provided around the exit of the Zeeman reducer 54. Each laser 70 has an appropriate angle and is reflected by the λ / 4 mirror 72, and the reflected lasers intersect in the capture space of the magneto-optical trap using the two-dimensional quadrupole magnetic field. The atoms existing in the intersecting space are restrained and decelerated in the Y direction by receiving radiation pressure from these lasers.

[0209] Fig.15 This is a diagram of the cooling atom generating device of Modification Example 7 viewed from the Z direction. In the above example, the axis of the atomic beam is parallel to the axis of the magnetic guide, but in Modification Example 7, the axis 74 of the atomic beam and the axis 76 of the magnetic guide may be non-parallel, and an angle θ may be set between their axes. By setting the angle θ, it is possible to prevent or suppress adverse effects on subsequent devices caused by heat radiation from the atomic furnace 52, residues of the atomic beam that have not been completely captured, and scattering of the laser used for Zeeman deceleration.

[0210] In order to prevent the unnecessary magnetic field from acting on the magneto-optical trap and magnetic guide using the two-dimensional quadrupole magnetic field, a compensation coil 78 may be provided at the outlet of the Zeeman reducer 54, or an inlet coil 80 may be provided for the magnetic guide and magnetic trap. This facilitates the adjustment for forming an ideal magnetic field distribution.

[0211] Reference Fig.17 Next, the cooling atom generating device of Modification Example 8 is described. In Modification Example 8, the atoms moved to the second region are guided to the subsequent device by two moving optical lattices intersecting at a non-zero angle. As a result, the first region and the subsequent device are spatially separated, and the naturally emitted photons generated in the first region can be suppressed from entering the subsequent device.

[0212] In the first region (the space indicated by reference numeral 32), atoms are trapped by a magneto-optical trap implemented by the laser group 18 (in its implementation, the mirror 100 and the λ / 4 mirror 102 are used). The trapped atoms relax to 3 In the P2 state, in the first embodiment, atoms are captured by the magnetic guide 104 using a quasi-three-dimensional quadrupole magnetic field. In the second embodiment, atoms are captured by the magnetic guide 104 using a two-dimensional quadrupole magnetic field. 3 The atoms in the P2 state move to the second region (the space indicated by the reference numeral 30) where the magnetic force, the radiation pressure of the second light, and the gravity are balanced, and are cooled with a narrow line width. In the second region, the cooled atoms are optically pumped to the third state that is insensitive to the magnetic field, and are captured by the first moving optical lattice 106. The trapped atoms are guided by the first moving optical lattice 106 and move to the point of intersection with the second moving optical lattice 108. At the point of intersection, the atoms captured by the first moving optical lattice 106 or a part of the atoms captured by the first moving optical lattice 106 are transferred to the second moving optical lattice 108 and captured by the second moving optical lattice 108. The trapped atoms are guided by the second moving optical lattice 108 and are guided to the clock transition space 92 surrounded by the light shielding wall 94 through the opening 94a.

[0213] Reference Fig.18 The cooling atom generating device of modification example 9 is described below. The two moving optical lattices 106 and 108 (that is, two moving optical lattices crossing at a non-zero angle) as one of the components of modification example 9 are realized by a bow-tie resonator coupled with mutually detuned lasers 118 and 120. In order to realize the bow-tie resonator, an incident mirror 110, mirrors 112, 114, and a concave mirror 116 are configured. By geometrically arranging the incident mirror 110, mirrors 112, 114, and concave mirror 116 so that the incident angle of the laser light with respect to the concave mirror 116 is close to vertical incidence, that is, by reducing θ in the figure, (1) the design of the stable condition of the resonator becomes easy, and (2) the beam diameters of the two crossing moving optical lattices 106 and 108 can be made equal.

[0214] As shown in FIG18 , each structure is arranged in such a manner that the second region (space indicated by reference numeral 30) and the clock transition space 92 are arranged on the optical path in the bow-tie resonator. When two mutually detuned lasers 118 and 120 for moving optical lattices are incident on the bow-tie resonator composed of the incident mirror 110, mirrors 112, 114, and concave mirror 116, the laser 118 is transmitted through the incident mirror 110, reflected by the mirror 112, passes through the second region, and is reflected by another mirror 114 and concave mirror 116, passes through the point where the optical path intersects, and is irradiated to one opening 94a of the clock transition space 92 surrounded by the light shielding wall 94. The other laser 120 for moving optical lattices is transmitted through the incident mirror 110, and is irradiated to the other opening 94b (the opening on the opposite side of the opening 94a) of the clock transition space. The laser light 118 irradiated to the opening 94a and the laser light 120 irradiated to the opening 94b pass through the clock transition space 92, respectively exit from the opposite openings, travel on opposite optical paths, and are reflected by the incident mirror 110 and recycled. That is, the laser light 118 traveling from the opening 94a to the clock transition space 92 is emitted from the opening 94b and recycled. The laser light 120 traveling from the opening 94b to the clock transition space 92 is emitted from the opening 94a and recycled.

[0215] In the second region, the cooled atoms are optically pumped to the third state insensitive to the magnetic field, and are captured by the first moving optical lattice 106 formed in the bow-tie resonator. The captured atoms are guided by the first moving optical lattice 106 and move to the point where the first moving optical lattice 106 and the second moving optical lattice 108 intersect. At the point of intersection, the atoms captured by the first moving optical lattice 106 or a part of the captured atoms are transferred to the second moving optical lattice 108, guided by the second moving optical lattice 108, and guided to the clock transition space 92 surrounded by the light shielding wall 94 through the opening 94a. Since the first region (the space indicated by the reference numeral 32) is spatially separated from the subsequent device (for example, the clock transition space 92), it is possible to suppress the natural emission photons generated in the first region from entering the subsequent device.

[0216] According to the first embodiment, the second embodiment, or their modified examples, atoms can be continuously cooled and output to a subsequent device. As a result, continuous measurement can be achieved in the subsequent device.

[0217] For example, the position of atoms trapped by a magneto-optical trap using laser light and a quadrupole magnetic field is similar to that of atoms in 3 If the positions of the atoms in the P2 state irradiated with the narrow linewidth cooling laser are the same, the atoms cannot be cooled efficiently. 3When the atom in the P2 state is cooled, the speed of the atom slows down and decays toward the center of the quadrupole magnetic field, that is, the zero magnetic field center, which causes Majorana flipping. The state of the atom changes from 3 The atoms will escape from the magnetic trap when the P2 state transitions.

[0218] In contrast, according to the first embodiment, the second embodiment or the modified example, the position where atoms are captured by the magneto-optical trap is the center of the quadrupole magnetic field, which is a zero magnetic field. On the other hand, the position where narrow linewidth cooling is performed is a position away from the center of the quadrupole magnetic field, where a limited bias magnetic field that can prevent Majorana flipping is applied. That is, atoms can be captured in a capture space equivalent to the first region, and the captured atoms can be moved to the position 30 or the minimum position 66 equivalent to the second region by gravity, magnetism, and the radiation pressure of the laser 68, and narrow linewidth cooling can be performed at the position 30 or the minimum position 66. In this way, atomic capture and narrow linewidth cooling can be performed in different states and places, respectively, so atomic capture and narrow linewidth cooling can be performed continuously. Moreover, by optically pumping the state of the atoms to the third state to release the cooled atoms from the magnetic trap, the cooled atomic gas can be continuously supplied to the subsequent device using a moving optical lattice, etc., and the subsequent device can continuously perform measurement.

[0219] As one of the means for guiding the atoms in the third state which have been sufficiently cooled in the second state from the second region to the subsequent device, the moving optical lattice technique is described as an example. As another means for guiding, a method using an optical dipole guide can also be considered.

[0220] <Structure of the optical lattice clock>

[0221] Reference Fig.19 A schematic configuration of an optical lattice clock 200 using a cooled atom generating device according to each embodiment will be described. Fig.19 2 is a block diagram showing the overall configuration of the optical lattice clock 200. Here, the optical lattice clock 200 is described as an example of a device using a cooling atom generating device, but the cooling atom generating device can of course be used in devices other than the optical lattice clock 200.

[0222] The optical lattice clock 200 includes, for example, a physics package 202 , an optical system device 204 , a control device 206 , and a PC (Personal Computer) 208 .

[0223] The physical package 202 includes the cooling atom generating device of the first or second embodiment, and is a device that captures the atomic group and seals it in the optical lattice to cause clock transition. The optical system device 204 is a device with optical devices such as a laser source for atom cooling, a laser source for atom capture, a laser source for clock transition excitation, and a laser frequency control device. In addition to sending laser light to the physical package 202, the optical system device 204 also receives the fluorescence signal emitted by the atomic group in the physical package 202 and converts it into an electrical signal and feeds it back to the laser source to match the resonance frequency of the atom. The control device 206 is a device that controls the physical package 202 and the optical system device 204. The control device 206, for example, performs the operation control of the physical package 202, the operation control of the optical system device 204, and the analysis processing such as the frequency analysis of the clock transition obtained by measurement. The function of the optical lattice clock 200 is realized by the cooperation of the physical package 202, the optical system device 204 and the control device 206.

[0224] PC208 is a general-purpose computer including a processor and a memory. The functions of PC208 are realized by executing software by hardware including a processor and a memory. An application for controlling the optical lattice clock 200 is installed in 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 a UI (User Interface) of the optical lattice clock 200. The user can start the optical lattice clock 200, measure time, and confirm the results through PC208.

[0225] In addition, a system including the physical package 202 and the components required for controlling the physical package 202 is sometimes referred to as a "physical package system". The components required for control may be included in the control device 206 or the PC 208, or may be included in the physical package 202. In addition, part or all of the functions of the control device 206 may also be included in the physical package 202.

[0226] In the physical package 202, the interior of the vacuum chamber is evacuated. As described with respect to the cooling atom generation device of the first and second embodiments, the atomic beam emitted from the atomic beam furnace is decelerated by the Zeeman decelerator and travels to the magneto-optical trap device. In the magneto-optical trap device, a magnetic field with a linear spatial gradient is formed with the capture space for capturing atoms as the center, and a laser for magneto-optical trap is irradiated. As a result, the atoms are cooled and captured by energy dissipation caused by laser cooling and recovery from the center of the trap. This is called magneto-optical trap of atoms. Afterwards, the atoms that relax to an energy level that can be magnetically captured are laser-cooled in the capture space of the two-dimensional magnetic guide and captured in the capture space formed by forces including magnetic force, gravity, and radiation pressure. In addition, the optical lattice beam is incident on the capture space and reflected by the optical resonator arranged in the vacuum cavity, thereby forming an optical lattice potential in which standing waves extend in the direction of travel of the optical lattice beam. The atomic group is captured by the optical lattice potential.

[0227] By slightly changing the frequency of the relative optical lattice beam, the optical lattice can be moved in the direction of travel of the optical lattice beam. The atomic group is moved to the clock transition spectroscopic region by the moving unit formed by the moving optical lattice. As a result, the clock transition space can be separated from the region where the thermal radiation from the high-temperature atomic beam furnace reaches or the region where the high-temperature atoms emitted from the atomic beam furnace are bathed. In addition, by separating the magneto-optical trap from the second capture space, it is avoided that the naturally emitted light generated in the magneto-optical trap acts on the clock transition space and generates an optical frequency shift of the clock transition in the subsequent device.

[0228] In the clock transition space, the atoms are irradiated with a frequency-controlled laser to perform high-precision spectrometry of the clock transition (i.e., the resonant transition of the atoms that serve as the reference of the clock) to measure the inherent and unchanging frequency of the atoms. Thus, an accurate atomic clock is achieved. In addition, spectrometry can also be performed in the capture space without moving the atomic group from the capture space to the clock transition space.

[0229] In order to improve the accuracy of atomic clocks, it is necessary to eliminate the disturbances surrounding the atoms and accurately read the frequency. It is particularly important to remove the frequency shift caused by the Doppler effect caused by the thermal motion of the atoms. In an optical lattice clock, the atoms are confined in a space that is sufficiently small compared to the wavelength of the clock laser by using an optical lattice generated by the interference of lasers to freeze the movement of the atoms. On the other hand, within the optical lattice, the frequency of the atoms will shift due to the laser that forms the optical lattice. Therefore, by selecting a specific wavelength and frequency called the "magic wavelength" or "magic frequency" as the optical lattice beam, the influence of the optical lattice on the resonant frequency can be eliminated.

[0230] As a result of the clock transition, the emitted light is received by the optical system device 204 and subjected to spectroscopic processing by the control device 206 to determine the frequency.

[0231] In the above description, the optical lattice clock is cited as an example. However, if it is a person skilled in the art, the technology of the first and second embodiments can also be applied to other than the optical lattice clock. Specifically, it can also be applied to atomic clocks other than optical lattice clocks or atom interferometers as interferometers using atoms. For example, it is also possible to constitute a physical package for an atomic clock containing a cooling atom generating device of the first or second embodiment, or a physical package for an atom interferometer. In addition, this embodiment can also be applied to various quantum information processing devices for atoms or ionized atoms. Quantum information processing equipment refers to a device that uses the quantum state of atoms or light for measurement, sensing, and information processing. In addition to atomic clocks and atom interferometers, magnetic field meters, electric field meters, quantum computers, quantum simulators, quantum repeaters, etc. can also be exemplified. In the physical package of the quantum information processing device, by using the technology of the embodiment, it can be processed continuously in the same way as the physical package of the optical lattice clock. In addition, it should be noted that in such a device, the clock transition space is sometimes not a space for the purpose of time measurement, but is only regarded as a space that causes clock transition spectroscopy.

[0232] In the above description, specific embodiments are shown for easy understanding, but these are merely examples of implementation, and various other implementations are possible.

[0233] Description of Reference Numerals

[0234] 10, 50 cooling atom generating device; 12, 52 atomic reactor; 14, 54 Zeeman reducer; 16, 56 magneto-optical trap device; 22, 60 magnetic field generating unit; 24 coil; 26, 62 permanent magnet; 64 stop coil.

Claims

1. A cooling atom generating device, characterized in that: Include: a first cooling unit that cools and traps atoms in a first state in a first region by using a first light and a first magnetic field; A magnetic trap unit that captures the atoms optically pumped to the second state by magnetic force; a second cooling unit for cooling the atoms in the second state by irradiating the atoms in the second state that have moved from the first region to the second region with a second light; as well as A supply unit supplies atoms to a subsequent device by optically pumping the atoms into a third state insensitive to a magnetic field in the second region, using a moving optical lattice or an optical dipole guide.

2. The cooling atom generating device according to claim 1, characterized in that: Make sure there are three mutually orthogonal axes. The magnetic trap unit moves atoms from the first region to the second region by forming a magnetic field distribution in which a magnetic field gradient in a direction of one of the three axes is weaker than magnetic field gradients in directions of other two of the three axes.

3. The cooling atom generating device according to claim 2, characterized in that: The one axis direction is the direction of gravity. The second region is a position where the magnetic force, gravity, and radiation pressure of the second light are balanced.

4. The cooling atom generating device according to claim 2, characterized in that: The one axis direction is the direction in which the radiation pressure of the second light acts. The second region is a position where the magnetic force and the radiation pressure of the second light are in balance.

5. The cooling atom generating device according to claim 3, characterized in that: The magnetic trap unit includes a coil and a permanent magnet, and the magnetic field distribution is formed by a magnetic field from the coil and a magnetic field from the permanent magnet.

6. The cooling atom generating device according to claim 2, characterized in that: The magnetic trap unit includes a permanent magnet that forms a two-dimensional quadrupole magnetic field on a plane defined by the two axes and a coil that forms a magnetic field in the one-axis direction. The magnetic field distribution is formed by the magnetic field from the permanent magnet and the magnetic field from the coil.

7. The cooling atom generating device according to any one of claims 1 to 6, characterized in that: The atom is a strontium atom.

8. The cooling atom generating device according to claim 7, characterized in that: The first light is a laser with a wavelength of 461 nm. The first state is 5s 21 S0 state.

9. The cooling atom generating device according to claim 8, characterized in that: The second light is a laser with a wavelength of 2.9 μm. The second state is 5s5p 3 P2 status.

10. The cooling atom generating device according to claim 5, characterized in that: The coil and the permanent magnet In the first region, a quadrupole magnetic field is generated with a zero magnetic field position as the center in such a manner that a magneto-optical trap is realized for the atoms in the first state by the first cooling unit. In the second region, a magnetic field distribution is formed in such a manner that the sum of the gravity acting on the atoms and the radiation pressure of the second light is balanced with the magnetic force acting on the atoms, The magnetic field distribution formed in the second region is a magnetic field distribution formed by a non-zero finite magnetic field and realizing a magnetic trap while preventing Majorana reversal.

11. The cooling atom generating device according to claim 1, characterized in that: further comprising a light shielding wall that optically blocks a straight path connecting the first area and the subsequent device, The first region and the second region are formed by being separated in space, The incident light of the natural emission generated in the first region on the subsequent device is suppressed by the light shielding wall.

12. The cooling atom generating device according to claim 1, characterized in that: further comprising a light shielding wall that optically blocks the first area from the subsequent device, The second region is optically connected to the subsequent device via two moving optical lattices that intersect at a non-zero angle. The supply unit supplies atoms to the subsequent device through the two moving optical lattices, The incident light of the natural emission generated in the first region on the subsequent device is suppressed by the light shielding wall.

13. The cooling atom generating device according to claim 12, characterized in that: The two moving optical lattices are formed by bow-tie resonators.

14. The cooling atom generating device according to claim 1, characterized in that: further comprising a light shielding wall that optically blocks the first area from the subsequent device, The second region and the subsequent device are optically connected via a plurality of moving optical lattices connected at a common intersection. The supply unit supplies atoms to the subsequent device through the plurality of moving optical lattices, The incident light of the natural emission generated in the first region on the subsequent device is suppressed by the light shielding wall.

15. A cooling atom generating device, characterized in that: Include: a first cooling unit that cools and traps atoms in a first state in a first region by using a first light and a first magnetic field; a unit for relaxing the state of atoms trapped in the first region to a second state by optical pumping generated in a laser cooling process; A unit for moving the atoms to a second region having a non-zero magnetic field by balancing the magnetic force acting on the atoms in the second state, the gravity, and the radiation pressure of the second light irradiated on the atoms in the second state; a second cooling unit configured to cool the atoms in the second state by irradiating the atoms in the second state with a second light in the second region; In the second region, a unit for optically pumping atoms into a third state that is insensitive to a magnetic field; as well as A unit for supplying atoms in the third state from the second region to a subsequent device by moving an optical lattice or an optical dipole guide, The atoms in the first state input into the first region are cooled by the first cooling unit and transition to the second state. The atoms in the second state move from the first region to the second region due to a balance among the magnetic force, gravity, and radiation pressure of the second light. The state of the atoms moved to the second region is changed to a third state by performing an optical pumping operation after being cooled by the second cooling unit. The atoms in the third state are captured by a moving optical lattice or an optical dipole guide, and are supplied from the second region to the subsequent device.

16. A cooling atom generation method, characterized in that: Include: A first cooling step, in the first region, cooling and trapping atoms in the first state by means of a first light and magnetic field; The magnetic trap step is to capture the atoms optically pumped to the second state by magnetic force; A step of moving atoms from the first region to the second region; a second cooling step of cooling the atoms in the second state by irradiating the atoms in the second state that have moved from the first region to the second region with a second light; as well as The supplying step is to supply the atoms to a subsequent device by optically pumping the atoms into a third state insensitive to a magnetic field in the second region, using a moving optical lattice or an optical dipole guide.

17. The cooling atom generation method according to claim 16, characterized in that: Make sure there are three mutually orthogonal axes. In the magnetic trap step, a magnetic field distribution is formed in which the magnetic field gradient in the direction of one of the three axes is weaker than the magnetic field gradient in the directions of the other two axes, so that gravity or the radiation pressure of the second light can be used to move atoms from the first region to the second region.

18. A physical package, characterized in that: Include: The cooling atom generating device according to claim 1; and A vacuum chamber enclosing the clock transition space of the configured atoms.

19. A physical package for an optical lattice clock, characterized in that: Comprising the physical package of claim 18.

20. A physical package for an atomic clock, characterized in that: Comprising the physical package of claim 18.

21. A physical package for an atomic interferometer, characterized in that: Comprising the physical package of claim 18.

22. A physical package for a quantum information processing device for atoms or ionized atoms, characterized in that: Comprising the physical package of claim 18.

23. A physical packaging system, characterized in that: Include: The physical package of claim 18; and A control device controls the actions of the physical package.

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