Ion trapping method and device

Abstract

The present invention provides an ion trapping method and device, which includes: applying radio frequency alternating current voltage or direct current voltage to multiple electrodes of a Paul trap to trap ions in three axial directions; focusing multiple laser beams from multiple directions through lenses to irradiate the ions to form a group of focused light spots with the waist center positions of the multiple laser beams overlapping with each other; modulating the shape of the focused light spots formed by each laser beam to form a group of optical dipole traps with long and short axes perpendicular to each other; adjusting the position of the optical dipole trap and / or the Paul trap so that the geometric center of the optical dipole trap coincides with the geometric center of the Paul trap; synchronously modulating the light intensity of each laser beam using an external modulation signal using an optoelectronic modulator; and modulating the modulation phase and modulation depth of each laser beam so that the first force generated by the optical dipole trap on the ions offsets the alternating current force generated by the Paul trap on the ions, thereby eliminating micro-motion of the ions in multiple axial directions of the Paul trap.

Description

Technical Field

[0001] At least one embodiment of the present invention relates to the fields of atoms, molecules, and optical technologies, and more particularly, to an ion trapping method and apparatus. Background Art

[0002] In the fields of atomic, molecular, and optical technology, the study of ions typically requires stable confinement within instruments using electromagnetic or optical methods, and the reduction of their motion to cryogenic temperatures (e.g., millikelvin, microkelvin, or even lower) through various cooling methods. In principle, any device that exerts an average restoring force on the ions, in a system isolated from the external environment, can confine them.

[0003] Existing ion trapping methods include classical ion traps, optical dipole traps, and simple combinations of classical and optical dipole traps. Paul traps utilize radio frequency alternating current (RF) electric fields and direct current (DC) electrostatic fields to confine ions. They are widely used in fields such as quantum computing, quantum information, and precision measurement. Depending on the radial and axial confinement conditions, the trapped ions can form one- to three-dimensional ionic crystals, with potential well depths reaching electron volts and a wide capture range, reaching millimeters. Penning traps utilize magnetic fields and DC electrostatic fields to confine ions. Their advantage is the ease of forming two-dimensional ionic crystals, which allows for a rich set of interaction schemes. Optical dipole traps, based on the radiation pressure of a focused laser beam, can be used to confine and move ions and atoms, with the advantage of preventing microscopic motion of the trapped ions.

[0004] The Paul trap has the disadvantage that the presence of the radio frequency electric field causes micromotion of the ions, limiting the overall cooling temperature of the ions. This limits the Paul trap's application in research such as high-precision optical clocks and cold ion-atom collisions. The Penning trap also suffers from the overall rotational motion of the ion crystal, which makes ion cooling difficult. The optical dipole trap has the disadvantage of a very shallow potential well depth (on the order of microelectronvolts), which prevents ion confinement for long periods of time. The trapped ions often have a lifetime of minutes, making it difficult to use in precision ion optical clocks requiring long trapping times. Simple combinations of these trapping methods, such as combining an optical dipole trap with a classical ion trap (Paul or Penning), can achieve ion confinement by simultaneously operating or switching between the two traps. The first method of opening the optical dipole trap and the ion trap at the same time still cannot solve the problem of ion micro-motion; the second method first uses a classical ion trap to capture ions, completes ion cooling in the trap, compensates the voltage of the ion trap, then opens the optical dipole trap, and finally closes the ion trap. This method ultimately traps ions solely with the help of the optical dipole trap. Although it can eliminate the influence of ion trap micro-motion, the potential energy of the optical dipole trap is shallow and cannot trap ions for a long time. Summary of the Invention

[0005] In order to solve at least one of the above-mentioned and other technical problems in the prior art, the present invention provides an ion trapping method and device, which can increase the depth of the potential well, eliminate the influence of ion micromotion, and realize long-term, micromotion-free ion trapping.

[0006] According to one aspect of the present invention, there is provided an ion trapping method, comprising: applying a radio frequency alternating current voltage or a direct current voltage to a plurality of electrodes of a Paul trap to Ions are trapped in three directions of the axis;

[0007] Using multiple laser beams, the multiple laser beams are focused by lenses from multiple directions to irradiate the ions, so as to form a set of focused light spots with the waist centers of the multiple laser beams overlapping with each other;

[0008] Modulating the shape of the focused light spot formed by each of the laser beams so that the light intensity of the beam waist of the focused light spot is distributed in an elliptical shape, and the major axes and minor axes of the plurality of ellipses are perpendicular to each other, thereby forming a group of optical dipole traps with major axes and minor axes perpendicular to each other;

[0009] Adjusting the position of the optical dipole trap and / or the Paul trap so that the geometric centers of the optical dipole trap and the Paul trap coincide with each other;

[0010] Using an electro-optical modulator to synchronously modulate the intensity of each of the laser beams using an external modulation signal, wherein the modulation signal has the same radio frequency frequency and phase as the Paul trap;

[0011] Modulate the modulation phase and modulation depth of each laser beam so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the Micro-motion of the above ions in multiple axial directions.

[0012] A spatial modulator is used to modulate the plurality of laser beams, and the ellipticity parameter of the beam waist of each laser beam is modulated to form a plurality of optical dipole traps with mutually perpendicular long and short axes. The optical dipole traps generate corresponding AC forces on the plurality of ions to eliminate the ions in the Paul trap. The micro motion of the above ions in multiple axial directions is realized in the above Paul trap. Trapping of one-dimensional ionic chains in multiple axial directions.

[0013] According to an embodiment of the present invention, the above-mentioned Paul well includes two pairs of electrode rods, the sub-electrode rods in the two pairs of the electrode rods are equal in length, each of the sub-electrode rods includes a middle electrode and end electrodes located on both sides of the middle electrode, and each pair of the electrode rods is arranged at diagonally opposite vertices of a square to form a three-dimensional potential well in the central area of ​​the above-mentioned Paul well.

[0014] According to an embodiment of the present invention, a radio frequency alternating current voltage is applied to the first middle electrodes of the sub-electrode rods of the first electrode rod pair of the two pairs of electrode rods to generate an alternating current electric field; a direct current voltage is applied to the end electrodes of the sub-electrode rods of the first electrode rod pair of the two pairs of electrode rods, and the second middle electrodes and the end electrodes of the sub-electrode rods of the second electrode rod pair of the two pairs of electrode rods to generate a direct current electric field;

[0015] The AC electric field generated by the first intermediate electrode and the DC electric field generated by the second intermediate electrode are The plane forms a pseudopotential to Trapping ions in a plane; the DC electric field generated by the end electrodes in the two pairs of electrode rods forms an electrostatic trapping potential in the z-axis direction to trap ions in the z-axis direction.

[0016] According to an embodiment of the present invention, the phases of the radio frequency alternating current voltages applied to the two first intermediate electrodes are the same.

[0017] According to an embodiment of the present invention, each of the above-mentioned focused light spots includes a first focused light spot and a second focused light spot;

[0018] The modulation phase of the first focused light spot differs from the phase of the radio frequency alternating current voltage by π, and the modulation phase of the second focused light spot is consistent with the phase of the radio frequency alternating current voltage.

[0019] According to an embodiment of the present invention, the range of the beam waist radius of each group of the above-mentioned focused light spots includes 0.1 ~100 .

[0020] According to an embodiment of the present invention, after the ions are trapped in the xy plane and in the z-axis direction, the ions are cooled using laser Doppler cooling technology.

[0021] According to another aspect of the present invention, there is provided an ion trapping device comprising:

[0022] The Paul trap is suitable for generating a DC electric field and an AC electric field by using an AC voltage and a DC voltage applied to a plurality of electrodes of the Paul trap. Ions are trapped in three directions of the axis;

[0023] Laser, suitable for generating multiple laser beams;

[0024] A focusing lens is used to focus multiple beams of the above lasers to form multiple focused laser beams, generate multiple focused light spots, and further form multiple groups of optical dipole traps; and

[0025] The photoelectric modulator is adapted to modulate the modulation phase and modulation depth of each of the above laser beams so that the first force exerted by the above optical dipole trap on the above ions offsets the AC force exerted by the above Paul trap on the above ions, thereby eliminating the first force exerted by the above optical dipole trap on the above ions. Micro-motion of the above ions in multiple axial directions.

[0026] According to an embodiment of the present invention, the Paul trap includes any one of a quadrupole Paul trap, a Paul trap of multiple DC electrodes, a Paul trap of multiple sheet electrodes, and a multipole Paul trap.

[0027] According to an embodiment of the present invention, the ion trapping device further includes:

[0028] The spatial light modulator is suitable for modulating the plurality of laser beams mentioned above, and modulating the ellipticity parameter of the beam waist of each laser beam to form a plurality of optical dipole traps whose major and minor axes are perpendicular to each other. The optical dipole traps generate corresponding AC forces on the plurality of ions to eliminate the ions in the Paul trap. The micro motion of the above ions in multiple axial directions is realized in the above Paul trap. Trapping of one-dimensional ionic chains in multiple axial directions.

[0029] According to the ion trapping method and device provided by the present invention, a radio frequency AC voltage or a DC voltage is applied to multiple electrodes of the Paul trap to The ions are trapped in three directions along the axis, and then multiple laser beams are used. The multiple laser beams are focused by lenses from multiple directions to irradiate the ions, so as to form a group of focused light spots with the waist center positions of the multiple laser beams overlapping with each other; the shape of the focused light spot formed by each laser beam is modulated so that the light intensity of the waist of the focused light spot is distributed in an elliptical shape, and the major axes and minor axes of the multiple ellipses are perpendicular to each other, thereby forming a group of optical dipole traps with major axes and minor axes perpendicular to each other; the position of the optical dipole trap and / or the Paul trap is adjusted so that the geometric center of the optical dipole trap coincides with the geometric center of the Paul trap; the intensity of each laser beam is synchronously modulated by an electro-optical modulator through an external modulation signal, and the modulation signal is the same as the radio frequency frequency and phase of the Paul trap; the modulation phase and modulation depth of each laser beam are modulated so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the The present invention is based on a composite trap composed of a Paul trap and an optical dipole trap. By modulating the laser, the first force exerted by the optical dipole trap on the ions offsets the AC force exerted by the Paul trap on the ions, thereby eliminating the ion micro-movement in the Paul trap. The micro-motion of ions in multiple axial directions increases the depth of the potential well, achieving long-term, micro-motion-free confinement of ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0031] Figure 1 Schematically shows a flow chart of an ion trapping method according to an embodiment of the present invention;

[0032] Figure 2 Schematic diagram showing two light beam modulation schemes in an ion trapping method according to an embodiment of the present invention, in which the AC restoring force generated by the optical dipole trap in multiple directions offsets the AC restoring force generated by the ion trap electric field;

[0033] Figure 3 A schematic diagram illustrating the working principle of an ion trapping method according to an embodiment of the present invention is shown;

[0034] Figure 4 Schematic diagram of the ion trapping method according to an embodiment of the present invention Working principle diagram in plane;

[0035] Figure 5 Schematically shows the relationship between the radio frequency alternating electric field and the laser light field intensity modulation of the composite trap in the ion trapping method according to an embodiment of the present invention;

[0036] Figure 6 Schematically shows a simulation diagram of the calculated pseudopotential well depth at the laser beam waist plane in the ion trapping method according to an embodiment of the present invention;

[0037] Figure 7 Schematically showing the comparison of the relationship between the single ion external micro-motion temperature and the stray electric field intensity for three methods: a composite trap, a common Paul trap, and a simple combination of a Paul trap and an optical dipole trap in the ion trapping method according to an embodiment of the present invention;

[0038] Figure 8 A diagram schematically illustrates the theoretical calculation relationship between the single ion external micro-motion temperature and the experimental condition error in the ion trapping method according to an embodiment of the present invention;

[0039] Figure 9 Schematic diagram of an ion trapping device according to another embodiment of the present invention Plan view diagram;

[0040] Figure 10Schematically illustrating the simulation calculation of three-dimensional ion-atom collision processes occurring in a composite trap and a conventional Paul trap in an ion trapping method according to an embodiment of the present invention; and

[0041] Table 1 schematically shows the laser wavelength and power required for common atom-ion pairs according to an embodiment of the present invention.

[0042] In the above drawings, the meanings of the reference numerals are as follows:

[0043] e2, e3 first electrode rod pair;

[0044] e2-first sub-electrode rod;

[0045] e3-second sub-electrode rod;

[0046] e22, e32-first intermediate electrodes;

[0047] e21, e23, e31, e33-first end electrodes;

[0048] e1, e4 second electrode rod pair;

[0049] e1-the third sub-electrode rod;

[0050] e4-the fourth sub-electrode rod;

[0051] e12, e42-second intermediate electrodes;

[0052] e11, e13, e41, e43-second end electrodes;

[0053] M1-reflector;

[0054] B1- beam combiner;

[0055] L-focusing lens;

[0056] L1-first focusing lens;

[0057] L2-second focusing lens;

[0058] S-RF high voltage source;

[0059] RF-radio frequency AC voltage;

[0060] DC-direct current voltage;

[0061] OT1-first optical dipole trap;

[0062] OT2-second optical dipole trap;

[0063] B1-first hollow laser;

[0064] B2 - Second hollow laser. DETAILED DESCRIPTION

[0065] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0066] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0067] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0068] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0069] In existing technologies, when using Paul traps to trap ions, the presence of radio frequency electric fields causes micromotion of the ions, limiting the overall cooling temperature limit of the ions. This restricts Paul traps in applications such as high-precision optical clocks and cold ion-atom collisions. When using Penning traps to trap ions, the ion crystal undergoes overall rotational motion, and this cyclotron motion also makes ion cooling difficult. The disadvantage of optical dipole traps is that the potential well depth is very shallow, and the trapped ion lifetime is often on the order of minutes, making it difficult to trap ions for long periods of time and difficult to apply to precision ion optical clocks requiring long trapping times. Even a simple combination of several trapping methods cannot simultaneously address the issues of ion micromotion and long-term ion trapping.

[0070] In view of this, the present invention provides an ion trapping method, which applies radio frequency AC voltage or DC voltage to multiple electrodes of the Paul trap to The ions are trapped in three directions along the axis, and then multiple laser beams are used. The multiple laser beams are focused by lenses from multiple directions to irradiate the ions, so as to form a group of focused light spots with the waist center positions of the multiple laser beams overlapping with each other; the shape of the focused light spot formed by each laser beam is modulated so that the light intensity of the waist of the focused light spot is distributed in an elliptical shape, and the major axes and minor axes of the multiple ellipses are perpendicular to each other, thereby forming a group of optical dipole traps with major axes and minor axes perpendicular to each other; the position of the optical dipole trap and / or the Paul trap is adjusted so that the geometric center of the optical dipole trap coincides with the geometric center of the Paul trap; the intensity of each laser beam is synchronously modulated by an electro-optical modulator through an external modulation signal, and the modulation signal is the same as the radio frequency frequency and phase of the Paul trap; the modulation phase and modulation depth of each laser beam are modulated so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the The present invention is based on a composite trap composed of a Paul trap and an optical dipole trap, so that the first force exerted by the optical dipole trap on the ions offsets the AC force exerted by the Paul trap on the ions, thereby eliminating the The micro-motion of ions in multiple axial directions increases the depth of the potential well, achieving long-term, micro-motion-free confinement of ions.

[0071] Figure 1 The flowchart of the ion trapping method according to an embodiment of the present invention is schematically shown.

[0072] According to some embodiments of the present invention, Figure 1 As shown, the ion trapping method includes operations S101 to S106.

[0073] In operation S101, a radio frequency alternating current voltage or a direct current voltage is applied to a plurality of electrodes of the Paul trap to generate a The ions are trapped in three directions.

[0074] In operation S102 , multiple laser beams are used. The multiple laser beams are focused by lenses from multiple directions and irradiated onto ions to form a group of focused light spots with beam waist centers of the multiple laser beams overlapping with each other.

[0075] In operation S103, the shape of the focused light spot formed by each laser beam is modulated so that the light intensity of the beam waist of the focused light spot is distributed in an elliptical shape, and the major axes and minor axes of the multiple ellipses are perpendicular to each other, thereby forming a group of optical dipole traps with major axes and minor axes perpendicular to each other.

[0076] In operation S104 , the position of the optical dipole trap and / or the Paul trap is adjusted so that the geometric center of the optical dipole trap coincides with the geometric center of the Paul trap.

[0077] In operation S105 , the intensity of each laser beam is synchronously modulated by an external modulation signal using an electro-optical modulator, where the modulation signal has the same radio frequency frequency and phase as the Paul trap.

[0078] In operation S106, the modulation phase and modulation depth of each laser beam are modulated so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the Micro-motion of ions in multiple axial directions.

[0079] According to some embodiments of the present invention, ions are trapped in the x-axis, y-axis, and z-axis directions by applying radio frequency alternating voltage or direct current voltage to multiple electrodes of a Paul trap, and multiple laser beams are focused and irradiated to the ions from multiple directions through lenses to form a group of focused light spots whose waist center positions of the multiple laser beams coincide with each other; the shape of the focused light spot formed by each laser beam is modulated so that the light intensity of the waist of the focused light spot is distributed in an elliptical shape, and the major axes and minor axes of the multiple ellipses are perpendicular to each other, thereby forming a group of optical dipole traps whose major axes and minor axes are perpendicular to each other; the position of the optical dipole trap and / or the Paul trap is adjusted so that the geometric center of the optical dipole trap coincides with the geometric center of the Paul trap; an electro-optical modulator is used to synchronously modulate the light intensity of each laser beam through an external modulation signal, and the modulation signal is the same as the radio frequency frequency and phase of the Paul trap; the modulation phase and modulation depth of the beam waist of each laser beam are modulated so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the first force generated by the optical dipole trap on the ions The micro-motion of ions in multiple axial directions increases the depth of the potential well and realizes the long-term, micro-motion-free confinement of ions.

[0080] According to some embodiments of the present invention, the position of the optical dipole trap and / or the Paul trap is adjusted so that the geometric centers of the optical dipole trap and the Paul trap coincide with each other; that is, the beam waist centers of the multiple focused laser beams coincide with the geometric center of the Paul trap.

[0081] According to some embodiments of the present invention, a Paul trap is a type of ion trap, wherein the geometric center axis of the Paul trap is the z-axis, and the trapped ions are placed in the Paul trap. When radio frequency voltage and direct current voltage are applied to the electrodes of the Paul trap, the trapped ions are subjected to direct current electric field forces in the x-axis, y-axis, and z-axis directions, while the trapped ions are only trapped in the z-axis direction. The plane is subjected to an AC electric field force. At this time, the trapped ions are Trapped in the plane, The trapped ions in the plane no longer move. Although the ions are also trapped and bound in the z-axis direction of the Paul trap, there is micro-motion of the ions in the z-axis direction, which means that the ions may escape from the Paul trap at any time.

[0082] According to some optional embodiments of the present invention, the Paul trap is a quadrupole Paul trap. The electrodes of a quadrupole Paul trap are primarily composed of four parallel metal rods, referred to as "quadrupole rods" or "electrode rods." By controlling the voltage applied to the four rods, charged particles can be trapped and manipulated. The four rods of the quadrupole Paul trap can be split into multiple independent electrodes. This multi-segmented structure allows the voltage on each electrode to be independently adjusted, thereby improving the precision of control over the electric field formed within the Paul trap and enabling complex ion movement, cooling, and interaction plasma manipulation operations.

[0083] According to some embodiments of the present invention, the focused light spot is elliptical, and the elliptical light intensity distribution causes the restoring force of the optical dipole trap to be different in different directions. Therefore, if the light intensity of the optical dipole trap is modulated, the optical dipole trap will generate AC restoring forces of different sizes in different directions. By selecting a modulation frequency consistent with the ion trap and configuring the combination of light spots and the modulation phase of each beam of light, the following conditions can be achieved: the AC restoring force generated by the optical dipole trap and the AC restoring force generated by the electric field of the ion trap can offset each other in the x-axis, y-axis, and z-axis directions, thereby offsetting all micro-motions of ions in three-dimensional space. The specific principle is as follows: the trap potential energy in the above-mentioned composite trap can be expressed as formula (1):

[0084] (1);

[0085] in, is the potential generated by the DC electric field of the ion trap, is the potential generated by the AC electric field, For the The light dipole potential generated by a focused light spot, For the The light intensity of each spot modulates the depth factor ( The value range of is [-1,1]. No modulation, When the laser is fully modulated, the motion range of the ions in the composite trap after laser cooling is less than 100 nm, which is much smaller than the size of the light dipole trap spot. At this time, the potential well felt by the ions can be approximately expanded into a simple harmonic potential form, which can be expressed as formulas (2), (3) and (4):

[0086] (2);

[0087] (3);

[0088] (4);

[0089] in, 、 、 Respectively in Directional DC electric field, AC electric field and The simple harmonic coefficient of the optical potential well is , , is an insignificant constant. To offset The AC restoring force in each direction requires the simple harmonic coefficient to satisfy formula (5):

[0090] (5);

[0091] in, , configure different focusing spot incident directions and spot elliptical shape ratios to achieve different Combination and selection The combination can realize the equality relationship of the above formula (5).

[0092] Figure 2 The diagram schematically shows two light beam modulation schemes in the ion trapping method according to an embodiment of the present invention, which enable the AC restoring force generated by the optical dipole trap in multiple directions to offset the AC restoring force generated by the ion trap electric field.

[0093] According to some embodiments of the present invention, Figure 2 As shown, Figure 2 In (a), light beam 1 is modulated sequentially by spatial light modulation module 1 and light intensity modulation module 1, while light beam 2 is modulated sequentially by spatial light modulation module 2 and light intensity modulation module 2. The modulated light beam 1 is reflected by reflector M1 to beam combiner B1, where it is combined with modulated light beam 2 to form a combined beam. The combined beam is then focused by first focusing lens L1 to the geometric center of the Paul well. To configure the beam shape and modulate the beam intensity, both light beams 1 and 2 are modulated by the spatial light modulation module and the light intensity modulation module. The spatial light modulation module is used to modulate the beam shape, while the light intensity modulation module is used to modulate the beam intensity. The order in which the spatial light modulation module and the light intensity modulation module are modulated is not restricted. The two beams can be modulated by the spatial light modulation module first and then by the light intensity modulation module, or they can be modulated by the light intensity modulation module first and then by the spatial light modulation module.

[0094] According to some embodiments of the present invention, a spatial modulator is used to modulate multiple laser beams, and the ellipticity parameter of the beam waist of each laser beam is modulated to form multiple sets of optical dipole traps with mutually perpendicular major and minor axes. The optical dipole traps generate corresponding AC forces on multiple ions to eliminate the The micro-motion of multiple ions in multiple axial directions is realized in the Paul trap. Trapping of one-dimensional ionic chains in multiple axial directions.

[0095] According to some embodiments of the present invention, the spatial light modulator includes any one of a pair of cylindrical lenses, a programmable liquid crystal spatial light modulator, and a micromirror array. For example, a pair of cylindrical lenses can transform a circular Gaussian spot into an elliptical spot. Alternatively, the spot can be deformed using a programmable liquid crystal spatial light modulator or a micromirror array. The light intensity modulator includes any one of an acousto-optic modulator, an electro-optic modulator, and an electro-optic absorber.

[0096] According to some embodiments of the present invention, Figure 2 In (b), light beam 1 and light beam 2 are modulated by the spatial light modulation module and the light intensity modulation module in sequence from two different directions and then focused to the geometric center of the Paul well by the focusing lens. Light beam 1 passes through the spatial light modulation module 1 and the light intensity modulation module 1 in sequence, and the modulated light beam 1 is focused to the geometric center of the Paul well by the first focusing lens L1; light beam 2 passes through the spatial light modulation module 2 and the light intensity modulation module 2 in sequence, and the modulated light beam 2 is focused to the geometric center of the Paul well by the first focusing lens L2.

[0097] According to some embodiments of the present invention, by combining the above Figure 2 (a) and Figure 2 The combination of the two beam modulation schemes in (b) can also achieve the cancellation of the restoring force. And from formula (5), it can be concluded that more than just two beams can be used to achieve the conditions for canceling the restoring force. Choosing more beam configurations will make it easier to achieve the conditions for simultaneously canceling the restoring force in three directions.

[0098] According to some embodiments of the present invention, a potential well, or optical dipole trap, can be generated in space by focusing laser light. This is due to the interaction between the light field in the spot produced by the focused laser and charged particles. The optical dipole trap is a physical structure formed by utilizing the characteristics of the laser spot. In an optical dipole trap, particles experience an attractive force within the light field, drawing them toward regions of higher light field intensity. This attraction, known as the optical dipole force, stems from the dipole interaction between light and atoms. This allows the optical dipole trap to trap ions and manipulate their movement, among other things.

[0099] According to some embodiments of the present invention, the potential well depth of the optical dipole trap is related to factors such as the laser power, laser wavelength, and focusing conditions. The higher the laser power and the stronger the light intensity, the deeper the depth of the formed optical dipole trap. The laser wavelength also affects the depth of the optical dipole trap. The interaction between lasers of different wavelengths and particles is different, resulting in different depths of the formed trap. Therefore, choosing the appropriate laser wavelength is crucial for achieving effective particle trapping. Focusing conditions such as focal length, beam quality, and spot size also affect the depth of the optical dipole trap. By changing the focusing conditions to ensure that the laser energy is highly concentrated in the center area of ​​the trap, the depth of the formed optical dipole trap can be increased.

[0100] According to some embodiments of the present invention, by modulating multiple focused laser beams so that the long axes and / or short axes of multiple optical dipole traps are perpendicular to each other, a three-dimensional trapping structure can be formed, which traps bound ions from multiple directions, improves the stability of the ion position in the trap, and enhances the ion trapping effect.

[0101] According to some embodiments of the present invention, the laser beam waist refers to the position where the beam radius of the laser beam is the smallest in the propagation direction. The laser beam radius at this position is the beam waist radius. The laser beam waist is a point where the energy and quality of the beam emitted by the laser are the best. Therefore, multiple focused laser beams are modulated so that the beam waist centers of the multiple focused laser beams coincide with the geometric center of the Paul trap, thereby enhancing the trapping effect on ions and improving the stability of ions in the trap center.

[0102] According to some embodiments of the present invention, ion micromotion in a Paul trap is divided into two types: external micromotion and internal micromotion. External micromotion occurs when a weak stray DC electric field causes ions to deviate from the center of the AC potential, causing them to experience the AC field and be driven to perform reciprocating micromotion. Internal micromotion occurs when ions move within the equivalent simple harmonic potential provided by the ion trap. The wave packets of these ions inevitably have a certain size distribution (even when the ions are cooled to absolute zero, the zero-point energy of their simple harmonic motion still results in non-zero wave packet sizes). Wave packets that deviate from the center of the trap are also driven by the AC field and produce micromotion. Due to the limitations of the Paul trap principle, internal micromotion cannot theoretically be offset. While external micromotion can theoretically be compensated by adjusting the Paul trap voltage, it is difficult to completely offset in practice due to experimental limitations such as the accuracy of the compensation voltage and practical factors such as voltage drift. The present invention utilizes a composite trap combining an optical dipole trap and a Paul trap. The force exerted by the optical dipole trap on the ions offsets the AC force exerted by the Paul trap on the ions, eliminating the effects of both external and internal micromotion on ions located at the trap center.

[0103] Figure 3 A schematic diagram illustrating the working principle of an ion trapping method according to an embodiment of the present invention is shown; Figure 4 Schematic diagram of the ion trapping method according to an embodiment of the present invention Schematic diagram of the working principle in the plane.

[0104] According to some embodiments of the present invention, Figure 3 and Figure 4 As shown, the Paul well includes two pairs of electrode rods, the sub-electrode rods in the two pairs of electrode rods are equal in length, each sub-electrode rod includes a middle electrode and end electrodes located on both sides of the middle electrode, and each pair of electrode rods is arranged at diagonally opposite vertices of a square to form a three-dimensional potential well in the central area of ​​the Paul well.

[0105] According to some embodiments of the present invention, by arranging each pair of electrode rods of the Paul trap at diagonally opposite vertices of a square, a three-dimensional potential well is formed in the center region of the Paul trap, thereby trapping and manipulating ions.

[0106] According to some embodiments of the present invention, the sub-electrode rods in the two pairs of electrode rods are of the same length, and the two pairs of electrode rods are aligned. The distances between the two end electrodes and the middle electrode of the sub-electrode rods in each pair of electrode rods are consistent.

[0107] According to some embodiments of the present invention, Figure 3 As shown, the Paul trap includes two pairs of electrode rods, a first electrode rod pair e2 and e3, and a second electrode rod pair e1 and e4. The first electrode rod pair e2 and e3 includes a first sub-electrode rod e2 and a second sub-electrode rod e3; the second electrode rod pair e1 and e4 includes a third sub-electrode rod e1 and a fourth sub-electrode rod e4. The first sub-electrode rod e2 includes a first intermediate electrode e22 and two first end electrodes e21 and e23, respectively, disposed on either side of the first intermediate electrode; the second sub-electrode rod e3 includes a first intermediate electrode e32 and two first end electrodes e31 and e33, respectively, disposed on either side of the first intermediate electrode; the third sub-electrode rod e1 includes a second intermediate electrode e12 and two second end electrodes e11 and e13, respectively, disposed on either side of the second intermediate electrode; and the fourth sub-electrode rod e4 includes a second intermediate electrode e42 and two second end electrodes e41 and e43, respectively, disposed on either side of the second intermediate electrode. Each sub-electrode rod in the first electrode rod pair e2, e3 and the second electrode rod pair e1, e4 may have the same structure and / or material, but the type of voltage applied to each part is different.

[0108] According to some embodiments of the present invention, a radio frequency alternating current voltage is applied to the first intermediate electrodes e22 and e32 of the sub-electrode rods of the first electrode rod pair in the two pairs of electrode rods to generate an alternating current electric field; a direct current voltage is applied to the end electrodes of the sub-electrode rods of the first electrode rod pair in the two pairs of electrode rods, and the second intermediate electrodes e12 and e42 and the end electrodes of the sub-electrode rods of the second electrode rod pair in the two pairs of electrode rods to generate a direct current electric field; the alternating current electric field generated by the first intermediate electrodes e22 and e32 and the direct current electric field generated by the second intermediate electrodes e12 and e42 are in the The plane forms a pseudopotential to Ions are trapped in the plane; the DC electric field generated by the end electrodes in the two pairs of electrode rods forms an electrostatic trapping potential in the z-axis direction to trap ions in the z-axis direction.

[0109] According to some embodiments of the present invention, an RF AC voltage is applied to the first intermediate electrodes e22 and e32 to generate an AC electric field, and a DC voltage is applied to the second intermediate electrodes e12 and e42 to generate a DC electric field, so that The plane forms a pseudopotential to Ions are trapped in a plane. A DC electric field is generated by applying a DC voltage to the first end electrodes e21, e23, e31, and e33, and the second end electrodes e11, e13, e41, and e43, thereby forming an electrostatic trapping potential in the z-axis direction to trap the ions in the z-axis. Consequently, the ions are subjected to certain forces in the x-, y-, and z-axis directions, achieving ion confinement. However, due to the limitations of the Paul trap itself, the ions still experience micro-motion, resulting in a short duration of ion confinement. Therefore, an optical dipole trap is required to generate an optical dipole force on the ions to offset their micro-motion, achieving long-term, micro-motion-free ion confinement.

[0110] According to some embodiments of the present invention, the first end electrodes e21, e23, e31, e33 and the second end electrodes e11, e13, e41, e43 are also called cap electrodes of the quadrupole Paul trap, and a DC voltage is applied to provide electrostatic confinement potential energy in the z-axis direction to achieve confinement of ions in the z-axis direction.

[0111] According to some embodiments of the present invention, the phases of the radio frequency alternating current voltages applied to the two first intermediate electrodes e22 and e32 are the same.

[0112] According to some embodiments of the present invention, by setting the phases of the RF AC voltages applied to the two first intermediate electrodes e22 and e32 to be the same, the AC electric fields generated on the two first intermediate electrodes e22 and e32 can be made the same, and the stability of the generated AC electric fields can be improved.

[0113] According to some embodiments of the present invention, the RF AC voltage is provided by a RF high voltage source S.

[0114] Figure 5 The diagram schematically illustrates the relationship between the radio frequency AC voltage of the composite trap and the modulation phase of the two light beams in the ion trapping method according to an embodiment of the present invention.

[0115] According to some embodiments of the present invention, each group of focused light spots includes a first focused light spot and a second focused light spot, wherein the modulation phase of the first focused light spot differs from the phase of the RF AC voltage by π, and the modulation phase of the second focused light spot is consistent with the phase of the RF AC voltage.

[0116] According to some embodiments of the present invention, by setting the modulation phase of the first focused light spot in the two focused light spots to differ from the phase of the radio frequency AC voltage by π, and the modulation phase of the second focused light spot to be consistent with the phase of the radio frequency AC voltage, the force conditions of ions in the Paul trap can be adjusted by only modulating the light intensity and beam waist radius in the two focused light spots, and appropriate light intensity and beam waist radius of the two focused light spots are selected so that the AC light dipole force generated by the two focused light spots on the ions just offsets the AC force generated by the AC electric field generated by the radio frequency AC voltage on the ions within the range of the laser beam waist radius.

[0117] According to some embodiments of the present invention, Figure 3 The function of the middle focusing lens L is to focus the laser beam to output focused laser light, form a focused light spot, and further form an optical dipole trap.

[0118] According to some embodiments of the present invention, Figure 4 As shown, the first focused light spot forms a first optical dipole well OT1, and the second focused light spot forms a second optical dipole well OT2. The long axis or short axis of the first optical dipole well OT1 and the second optical dipole well OT2 are perpendicular to each other. Figure 4 The horizontal axis coordinate t represents time, and the vertical axis represents amplitude. Figure 4 It can be seen that the modulation frequency of the first optical dipole well OT1 and the second optical dipole well OT2 is the same; the modulation phase of the light intensity of the first optical dipole well OT1 differs from the phase of the RF AC voltage by π; and the modulation phase of the light intensity of the second optical dipole well OT2 is consistent with the phase of the RF AC voltage.

[0119] According to some embodiments of the present invention, the modulation frequency of the multi-beam focused laser is the same as the frequency of the radio frequency AC voltage. The multi-beam focused laser generates multiple focused light spots, each of which is elliptical in shape, with the long axes of at least two of the focused light spots perpendicular to each other. This is equivalent to an optical tweezer with two mutually perpendicular tight-binding directions. The tight-binding direction is typically the direction of maximum intensity gradient in the optical tweezers potential well. The optical tweezers primarily utilize a chip-based photon resonance capture technology for optical trapping. The force applied to the ions in the Paul trap is adjusted by modulating the intensity of the multi-beam focused laser.

[0120] According to some embodiments of the present invention, factors such as the beam waist radius of each laser beam, the ellipticity parameter of the beam waist, the modulation phase and modulation depth, the beam propagation direction, the ellipticity of the generated light spot, and the depth and phase of the laser light intensity can all affect the force exerted by the laser on the ions.

[0121] According to some embodiments of the present invention, the range of the beam waist radius of each group of focused light spots includes 0.1 ~100 .

[0122] According to some embodiments of the present invention, the beam waist radius of the laser is in the sub-micron range.

[0123] According to some embodiments of the present invention, after the ions are trapped in the xy plane and in the z-axis direction, the ions are cooled using laser Doppler cooling technology.

[0124] According to some embodiments of the present invention, trapped ions are cooled using laser Doppler cooling technology, achieving micromotion-free trapping of cold ions, lower temperatures of trapped single ions, and insensitivity to stray electric fields. This technology can be applied to fields such as high-precision single-ion optical clocks, cold atom-ion chemical reactions, and cold molecular ion synthesis. Throughout the cooling process, the Paul trap remains open, and the composite Paul trap and optical dipole trap retain their Paul trap properties within a large, millimeter-scale area around the periphery, allowing the entire composite potential well to stably confine ions.

[0125] According to some optional embodiments of the present invention, the ion cooling method includes any one of laser Doppler cooling, electromagnetic induction transparent cooling and sideband cooling.

[0126] According to some embodiments of the present invention, after the trapped ions are cooled, their temperature is relatively low, on the order of mK. Under this condition, the motion range of the ions in the trap is less than 100 nm, which is much smaller than the range of the laser beam waist radius.

[0127] Figure 6 The figure schematically shows a simulation diagram of the calculated pseudopotential well depth at the laser beam waist plane in the ion trapping method according to an embodiment of the present invention.

[0128] According to some embodiments of the present invention, the total pseudopotential of the potential well is formed by adding a DC potential and an AC pseudopotential. Figure 6 (a) represents the total pseudopotential near the center of the well in the x-axis direction of the beam waist plane; Figure 6 (b) in the Figure 6 The enlarged view of the central area of ​​(a) in the figure, the solid line is the total pseudopotential, the dashed line is the DC potential of the composite well, and the dotted line is the AC pseudopotential of the composite well. Figure 6 From (a) in the figure, we can see that the potential well is deep and can trap ions close to room temperature. Figure 6 As can be seen from (b) in the figure, the AC pseudopotential is flat and close to 0 in the range near the center, which means that the total AC force on the ion is also close to 0, that is, the optical dipole force generated by the optical dipole trap formed by the focused laser on the ion offsets the AC force generated by the Paul trap on the ion.

[0129] Figure 7 A diagram schematically shows the relationship between the single ion external micro-motion temperature and the stray electric field intensity for three methods, namely, a composite trap, a common Paul trap, and a simple combination of a Paul trap and an optical dipole trap, in the ion trapping method according to an embodiment of the present invention.

[0130] According to some embodiments of the present invention, when performing simulation calculations, the direction of the stray electric field is taken as (1, 1, 1), such as Figure 7 As shown, the horizontal axis represents the stray electric field E, in V / m; the vertical axis represents the temperature , in nK. HybridTrap (ZATC) represents the relationship between the external micro-motion temperature and the stray electric field strength of a single ion in a composite trap; HybridTrap (NoModulation) represents the relationship between the external micro-motion temperature and the stray electric field strength of a single ion in a simple combination of a Paul trap and an optical dipole trap; and PaulTrap represents the relationship between the external micro-motion temperature and the stray electric field strength of a single ion in a conventional Paul trap. Figure 7 It can be seen that the ion external micromotion temperature of the composite trap is significantly lower than that of the other two traps in the presence of a lower stray electric field, and can still maintain a low temperature of the nanokelvin level under the condition of a stray electric field of 1 V / m.

[0131] Figure 8 The figure schematically shows the theoretical calculation relationship between the single ion external micro-motion temperature and the experimental condition error in the ion trapping method according to an embodiment of the present invention.

[0132] According to some embodiments of the present invention, there are two technical errors in the ion trapping method that need to be considered. The first error is the alignment error between the optical dipole trap and the center of the Paul trap. The offset distance between the geometric center of the optical dipole trap and the center of the Paul trap is , the unit of offset distance is nm; the second error is the intensity modulation error of the optical dipole trap, which leads to the AC force generated by the Paul trap on the ion not being completely offset. The part that is not offset is recorded as the residual AC force , the remaining AC force The initial AC force generated by the radio frequency AC electric field on the ions in the original Paul trap The ratio is recorded as , . Figure 8 Demonstrates the relationship between the temperature and the offset distance of the micro-motion of a single ion as well as The relationship between the two experimental errors is given by Figure 8 It can be seen that the ion's external micromotion temperature can still be maintained at a low temperature of approximately 100 nK with an alignment error of 50 nm and a residual AC force of 5%. The present invention can control the ion alignment error in the optical field to less than 10 nm, and the measurement accuracy of the ion trap AC voltage to less than 1%. Therefore, both errors can be well controlled, thereby achieving ultra-low temperature ion confinement in the composite trap.

[0133] Another aspect of the present invention provides an ion trapping device, comprising a Paul trap, a laser, a focusing lens, and an electro-optical modulator. The Paul trap is suitable for generating a DC electric field and an AC electric field by applying an AC voltage and a DC voltage to a plurality of electrodes of the Paul trap. The laser is suitable for generating multiple laser beams. The focusing lens L is suitable for focusing multiple laser beams to form multiple focused laser beams, generate multiple focused light spots, and then form multiple groups of optical dipole traps. The photoelectric modulator modulates the modulation phase and modulation depth of each laser beam so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the Micro-motion of ions in multiple axial directions.

[0134] According to some embodiments of the present invention, by using a Paul trap and applying an AC voltage and a DC voltage to The ions are trapped in the three directions of the axis, and then multiple laser beams are generated by the laser. The multiple laser beams are focused by the focusing lens L to form multiple focused laser beams to form multiple sets of optical dipole traps. Finally, the modulation phase and modulation depth of each laser beam are modulated by the photoelectric modulator so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the The micro-motion of ions in multiple axial directions increases the depth of the potential well and realizes the long-term, micro-motion-free confinement of ions.

[0135] According to some embodiments of the present invention, the Paul trap includes any one of a quadrupole Paul trap, a Paul trap of multiple DC electrodes, a Paul trap of multiple sheet electrodes, and a multipole Paul trap.

[0136] Figure 9 Schematic diagram of an ion trapping device according to another embodiment of the present invention Plan view diagram.

[0137] According to some embodiments of the present invention, Figure 9As shown, the Paul trap in the ion trapping device is a Paul trap composed of multiple thin sheet electrodes. The only difference between a Paul trap composed of multiple sheet electrodes and a quadrupole Paul trap is the electrode shape and structure. However, the electrode grouping and number are the same, and the voltage applied to the multiple sheet electrodes is the same as for a quadrupole Paul trap. The focusing lens includes a first focusing lens L1 and a second focusing lens L2, placed along the line connecting the DC and AC electrodes, respectively. Both laser beams generated by the laser are hollow lasers: the first hollow laser B1 and the second hollow laser B2. The first hollow laser B1 and the second hollow laser B2 form two focused spots, OT1 and OT2, respectively, at the center of the Paul trap composed of multiple sheet electrodes. The first hollow laser B1 irradiates along the line connecting the DC electrodes, while the second hollow laser B2 irradiates along the line connecting the AC electrodes.

[0138] According to some embodiments of the present invention, hollow laser refers to a special light field distribution in which the center intensity of a laser beam is low and the edge intensity is high during transmission. This type of laser beam has a lower energy density in the central area and a higher energy density in the edge area, presenting a "hollow" form. The realization of hollow laser usually relies on specific optical elements and control technologies. For example, the use of phase plates, spatial light modulators or special laser resonant cavities can accurately control the laser beam to present a hollow light field distribution. The optical dipole trap formed by the hollow laser can improve the accuracy of the manipulation of ions or charged particles, and realize the confinement, movement and interaction of ions or charged particles.

[0139] According to some embodiments of the present invention, the ion trapping device further comprises a spatial light modulator, which is adapted to modulate multiple laser beams and modulate the ellipticity parameter of the beam waist of each laser beam to form multiple sets of optical dipole traps with mutually perpendicular major and minor axes, and the optical dipole traps generate corresponding AC forces on multiple ions to eliminate the effects of the Paul trap on the ions. The micro-motion of multiple ions in multiple axial directions is realized in the Paul trap. Trapping of one-dimensional ionic chains in multiple axial directions.

[0140] According to some embodiments of the present invention, a spatial light modulator can be provided to modulate multiple laser beams so that the laser beams in the Paul trap are A combination of multiple focused light spots is formed in multiple axial directions, and the combination of multiple focused light spots is modulated respectively, so that the light dipole force generated by the light dipole trap on the ions acts on Each ion on the multi-axis ion chain eliminates the micro-motion of multiple ions on the ion chain to achieve The trapping of one-dimensional ion chains in multiple axial directions can be applied to the research of cold atom-ion bound states and low-temperature chemical reactions in cold ion-atom mixed systems.

[0141] According to some embodiments of the present invention, ion trapping methods and apparatus can be used to reduce the heating of ions by radio frequency AC forces during cold ion-atom collisions, thereby significantly extending the lifetime of the generated quasi-molecular ion bound state. For example, an ytterbium ion with a mass number of 172 and a unit positive charge The collision process with the rubidium atom Rb with a mass number of 87.

[0142] According to some embodiments of the present invention, in a cold atomic-ion mixing system, atoms approaching the ions are polarized by the Coulomb force of the ions, resulting in an attractive force between the ions and atoms that is inversely proportional to the fourth power of the distance between them. This attraction causes the ions' motion to cease to be adiabatic during a single RF alternating current (RF) cycle, causing the RF electric field to perform work on the ions, raising the temperature of the cold mixing system and impacting subsequent cold chemistry research.

[0143] Table 1

[0144]

[0145] According to some embodiments of the present invention, Table 1 schematically shows the laser wavelength and power required for common atom-ion pairs according to embodiments of the present invention. As shown in Table 1, the laser wavelength and power selected for different ion-atom combinations are different, where is the laser wavelength in nm, P is the laser power in W, is the energy of the bound state of an atom or ion, is the Boltzmann constant, is the equivalent temperature, expressed in nanokelvins. To ensure that the composite trap only acts on the ion and leaves the ground-state rubidium atom Rb unaffected, an appropriate laser wavelength must be selected according to Table 1. For a single ion in a Paul trap, the electric field performs zero work on the ion during each cycle of the RF voltage (RF), meaning it is not heated by the electric field. Because there is virtually no AC force within the micrometer-scale region at the center of the composite trap, the ion undergoes virtually no energy exchange with the RF field, resulting in a nearly adiabatic ion-atom motion. This allows for a long, low-temperature, quasi-bound ion-atom state.

[0146] Figure 10 The diagram schematically illustrates a simulation calculation of a three-dimensional ion-atom collision process occurring in a composite trap and a common Paul trap in an ion trapping method according to an embodiment of the present invention.

[0147] According to some embodiments of the present invention, Figure 10The horizontal axis represents time t, in μs; the vertical axis represents the distance in the x-axis, y-axis, and z-axis directions, in nm. Figure 10 As shown, Figure 10 (a) Figure 10 (b) and Figure 10 (c) in the figure are the collision processes of ytterbium ions and rubidium atoms in the composite trap in the ion trapping method or device in the x-axis, y-axis, and z-axis directions, respectively. Figure 10 (a) Figure 10 (b) and Figure 10 From (c) in the figure, it can be seen that within 120 μs, neither the ytterbium ions nor the rubidium atoms escape from the composite trap. Figure 10 (d) Figure 10 (e) and Figure 10 (f) in the figure are the collision processes of ytterbium ions and rubidium atoms in the three directions of x-axis, y-axis and z-axis in the ordinary Paul trap, respectively. Figure 10 (d) Figure 10 (e) and Figure 10 In (f), we can see that within the time range before 20 μs, the rubidium atom has escaped from the ordinary Paul trap, and the motion trajectory of the rubidium atom cannot be observed within the time range after 20 μs. Figure 10 It can be seen that the collision process of ytterbium ions and rubidium atoms in the composite trap in the ion trapping method or device is relatively long, indicating that the lifetime of the ion-atom bound state is prolonged in the composite trap. The ion trapping method and device provided by the present invention improve the stability of ions and / or atoms in the center of the trap, and realize the long-term, micro-motion-free trapping of ions and / or atoms.

[0148] Those skilled in the art will appreciate that various combinations and / or combinations of features described in the various embodiments and / or claims of the present invention may be made, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, various combinations and / or combinations of features described in the various embodiments and / or claims of the present invention may be made, without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0149] The above describes embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which are intended to fall within the scope of the present invention.

Claims

1. An ion trapping method, characterized in that: include: Apply radio frequency AC voltage or DC voltage to multiple electrodes of the Paul trap to Ions are trapped in three directions of the axis; Using multiple laser beams, the multiple laser beams are focused by lenses from multiple directions to irradiate the ions, so as to form a set of focused light spots with the waist centers of the multiple laser beams overlapping with each other; Modulating the shape of the focused light spot formed by each laser beam so that the light intensity of the beam waist of the focused light spot is distributed in an elliptical shape, and the major axes and minor axes of the multiple ellipses are perpendicular to each other, thereby forming a group of optical dipole traps with major axes and minor axes perpendicular to each other; Adjusting the position of the optical dipole trap and / or the Paul trap so that the geometric center of the optical dipole trap coincides with the geometric center of the Paul trap; Using an electro-optical modulator to synchronously modulate the intensity of each laser beam through an external modulation signal, wherein the modulation signal has the same radio frequency frequency and phase as the Paul trap; Modulate the modulation phase and modulation depth of each laser beam so that the first force generated by the optical dipole trap on the ions offsets the AC force generated by the Paul trap on the ions, thereby eliminating the Micro-motion of the ions in multiple axial directions.

2. The ion trapping method according to claim 1, wherein: A spatial modulator is used to modulate multiple beams of the laser beam, and the ellipticity parameter of the beam waist of each laser beam is modulated to form multiple groups of optical dipole traps with long axes and short axes perpendicular to each other. The optical dipole traps generate corresponding AC forces on multiple ions to eliminate the The micro motion of the ions in the multiple axial directions is realized in the Paul trap. Trapping of one-dimensional ionic chains in multiple axial directions.

3. The ion trapping method according to claim 2, wherein: The Paul well includes two pairs of electrode rods, the sub-electrode rods in the two pairs of electrode rods are equal in length, each of the sub-electrode rods includes a middle electrode and end electrodes located on both sides of the middle electrode, and each pair of electrode rods is arranged at diagonally opposite vertices of a square to form a three-dimensional potential well in the central area of ​​the Paul well.

4. The ion trapping method according to claim 3, wherein: A radio frequency alternating current voltage is applied to the first middle electrodes of the sub-electrode rods of the first electrode rod pair of the two pairs of electrode rods to generate an alternating current electric field; a direct current voltage is applied to the end electrodes of the sub-electrode rods of the first electrode rod pair of the two pairs of electrode rods, and the second middle electrodes and the end electrodes of the sub-electrode rods of the second electrode rod pair of the two pairs of electrode rods to generate a direct current electric field; The alternating current electric field generated by the first intermediate electrode and the direct current electric field generated by the second intermediate electrode are The plane forms a pseudopotential to Ions are trapped in the plane; the DC electric field generated by the end electrodes in the two pairs of electrode rods forms an electrostatic trapping potential in the z-axis direction to trap ions in the z-axis direction.

5. The ion trapping method according to claim 4, wherein: The phases of the radio frequency alternating current voltages applied to the two first intermediate electrodes are the same.

6. The ion trapping method according to claim 5, characterized in that: Each group of focused light spots includes a first focused light spot and a second focused light spot; The modulation phase of the first focused light spot differs from the phase of the radio frequency alternating current voltage by π, and the modulation phase of the second focused light spot is consistent with the phase of the radio frequency alternating current voltage.

7. The ion trapping method according to claim 6, wherein: The range of the waist radius of each group of focused light spots includes 0.1 ~100 .

8. An ion trapping device, using the ion trapping method according to any one of claims 1 to 7, characterized in that: include: The Paul trap is suitable for generating a DC electric field and an AC electric field by using an AC voltage and a DC voltage applied to a plurality of electrodes of the Paul trap. Ions are trapped in three directions of the axis; Laser, suitable for generating multiple laser beams; A focusing lens is used to focus the multiple laser beams to form multiple focused laser beams, generate multiple focused light spots, and further form multiple groups of optical dipole traps; as well as The photoelectric modulator is adapted to modulate the modulation phase and modulation depth of each beam of the laser so that the first force exerted by the optical dipole trap on the ions offsets the AC force exerted by the Paul trap on the ions, thereby eliminating the first force exerted by the Paul trap on the ions. Micro-motion of the ions in multiple axial directions.

9. The ion trapping device according to claim 8, wherein: The Paul trap includes any one of a quadrupole Paul trap, a Paul trap of multiple DC electrodes, a Paul trap of multiple sheet electrodes, and a multipole Paul trap.

10. The ion trapping device according to claim 9, wherein: Also includes: A spatial light modulator is used to modulate multiple beams of the laser beam, and modulate the ellipticity parameter of the beam waist of each laser beam to form multiple groups of optical dipole traps with long and short axes perpendicular to each other, and the optical dipole traps generate corresponding AC forces on multiple ions to eliminate the ions in the Paul trap. The micro motion of the ions in the multiple axial directions is realized in the Paul trap. Trapping of one-dimensional ionic chains in multiple axial directions.

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