Ion trap chip, system, ion trapping method and quantum device

Abstract

The application discloses an ion trap chip, a system, an ion trapping method and a quantum device, relates to the technical field of quantum computing and quantum precision measurement, and the chip comprises a piezoelectric substrate; an acoustic surface wave excitation unit is configured to form a two-dimensional acoustic surface wave sound field in a central region of the piezoelectric substrate when receiving an alternating driving signal; the two-dimensional acoustic surface wave sound field generates a spatial periodic alternating electric field synchronous with the acoustic surface wave in the central region through the piezoelectric effect of the piezoelectric substrate; and the spatial periodic alternating electric field forms a pseudo-potential for confining charged ions.

Description

Technical Field

[0001] This application relates to the fields of quantum computing and quantum precision measurement technology, and in particular to an ion trap chip, system, ion trapping method and quantum device. Background Technology

[0002] Ion trap technology is one of the core technologies in fields such as quantum computing, atomic clocks, and precision spectroscopy. As the scale of qubits increases and the system integration becomes more sophisticated, ion trap platforms place higher demands on addressability, scalability, and high optical accessibility. However, bottlenecks still exist in some cases regarding scalability, noise and crosstalk suppression, and optimization of the quantum-classical interface.

[0003] Currently, ion trap technology has the following main drawbacks: First, as the number of qubits increases, the control complexity, electrode crosstalk, and difficulty of coordinated measurement and control also increase, making large-scale integrated engineering difficult to implement; Second, the high metal coverage on the chip surface limits optical access efficiency, affecting ion cooling, state preparation, quantum state reading, and quantum gate operation; Third, the trap structure is difficult to dynamically adjust after manufacturing, limiting the ability to flexibly control the potential trap array parameters and ion positions. Summary of the Invention

[0004] The purpose of this application is to provide an ion trap chip, system, ion trapping method, and quantum device that uses a spatially periodic alternating electric field induced by the piezoelectric effect of surface acoustic waves as a radial ion confinement radio frequency source, fundamentally avoiding the placement of radio frequency electrodes in the central region, and utilizing the tunability of the frequency, phase, and amplitude of the SAW driving signal to achieve dynamic reconstruction of the potential trap array.

[0005] To achieve the above objectives, this application provides the following solution:

[0006] In a first aspect, this application provides an ion trap chip, comprising:

[0007] Piezoelectric substrate (100);

[0008] A surface acoustic wave excitation unit (200) is disposed on the piezoelectric substrate (100) and is configured to form a two-dimensional surface acoustic wave sound field in the central region (300) of the piezoelectric substrate (100) when receiving an alternating drive signal. The field is composed of at least two independently controllable surface acoustic wave components.

[0009] The two-dimensional surface acoustic wave sound field generates a spatial periodic alternating electric field synchronized with the surface acoustic wave in the central region (300) through the piezoelectric effect of the piezoelectric substrate (100); the spatial periodic alternating electric field forms a pseudopotential for confining charged ions in a planar direction parallel to the upper surface of the piezoelectric substrate (100) under the time average of the sound field node positions within the oscillation period.

[0010] Secondly, this application provides an ion trap system based on the aforementioned ion trap chip, comprising:

[0011] A radio frequency drive source is electrically connected to the surface acoustic wave excitation unit (200) to provide an alternating drive signal;

[0012] A DC or quasi-static power supply, electrically connected to the terminal electrode assembly (400), is used to provide an axial limiting voltage;

[0013] A vacuum chamber, inside which the planar ion trap chip is placed.

[0014] Thirdly, this application provides an ion trapping method based on the aforementioned ion trap chip, comprising:

[0015] S1. Charged ions are loaded into the central region (300) under vacuum conditions;

[0016] S2. Apply an alternating driving signal to the surface acoustic wave excitation unit (200) so that the surface acoustic wave excitation unit (200) forms a two-dimensional surface acoustic wave sound field in the central region (300) composed of at least two independent and controllable surface acoustic wave components.

[0017] S3. The two-dimensional surface acoustic wave sound field is induced by the piezoelectric effect to generate a spatial periodic alternating electric field, forming a two-dimensional pseudopotential minimum point at the sound field node position under the time average within the oscillation period, thus confining the charged ions at the pseudopotential minimum point.

[0018] S4. An axial confinement electric field is applied through the terminal electrode assembly (400), and the three-dimensional trapping of charged ions is achieved in conjunction with the pseudopotential minimum point.

[0019] Fourthly, this application provides a quantum device, including the aforementioned ion trap chip or ion trap system; the quantum device is a quantum computer, a quantum simulator, an atomic clock, a quantum frequency standard, or a quantum sensor.

[0020] According to the specific embodiments provided in this application, this application has the following technical effects:

[0021] This application provides an ion trap chip, system, ion confinement method, and quantum device. By designing a planar ion trap chip structure based on a surface acoustic wave (SAW) induced electric field, a central region without radio frequency (RF) metal electrodes is achieved. Secondly, a two-dimensional SAW sound field, composed of at least two independently controllable SAW components superimposed, is formed in the central region on a piezoelectric substrate using a SAW excitation unit. This field is then converted into a spatially periodic alternating electric field using the piezoelectric effect. This alternating electric field forms a pseudopotential minimum at the sound field node locations within the oscillation period, achieving effective confinement of charged ions in a planar direction parallel to the surface of the piezoelectric substrate. Furthermore, the axial confinement electric field provided by the DC or quasi-static voltage applied by the end electrode assembly, in synergy with the in-plane pseudopotential minimum, successfully achieves three-dimensional ion confinement. The technical solution of this application achieves structural simplification and integration, eliminating the adverse effects of traditional electrodes. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a top view of the ion trap chip provided in the embodiments of this application;

[0024] Figure 1a This is a side view schematic diagram of the end electrode assembly adopting a plate-shaped electrode structure in the embodiments of this application;

[0025] Figure 1b This is a side view schematic diagram of the end electrode assembly adopting a needle-shaped electrode structure in an embodiment of this application;

[0026] Figure 2 The two-dimensional pseudopotential U induced by the two-dimensional standing wave of surface acoustic waves in the embodiments of this application is... pseudo Simulation diagram of (x,y) distribution;

[0027] Figure 3 This is a schematic diagram of the overall framework of the ion trap system in the embodiments of this application;

[0028] Figure 4 The pseudopotential U induced by the two-dimensional standing wave SAW in the embodiments of this application is... pseudo (x,y) Simulation cloud plot and 3D pseudopotential surface plot.

[0029] Figure label:

[0030] 100 - Piezoelectric substrate, 200 - Surface acoustic wave excitation unit, 300 - Central region, 400 - End electrode assembly. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] In some cases, the following ion trap technologies are frequently used in technical solutions:

[0033] (1) Linear ion trap: It consists of multiple parallel symmetrical electrodes, which are suitable for forming ion chains and coordinating manipulation. The structure and principle are relatively simple and the engineering implementation threshold is low. However, this structure is limited in terms of two-dimensional array expansion and chip-level high-density integration, making it difficult to meet the needs of large-scale quantum bit array expansion.

[0034] (2) Surface electrode ion trap (SET): Electrode arrays are fabricated on a planar substrate in micro- and nano-scale. A three-dimensional trapping potential field is generated by the combination of radio frequency and DC electrodes. It has good two-dimensional planar expansion capability and is compatible with semiconductor processes. However, the high metal coverage on the chip surface can easily block the optical path and introduce heating noise. At the same time, when multiple bits work in parallel, electrode crosstalk and environmental electromagnetic noise are significantly superimposed, which limits the improvement of quantum gate fidelity and increases the cost of subsequent noise reduction and calibration.

[0035] (3) QCCD ion trap (quantum charge-coupled ion trap): The chip is divided into a storage area, a logic gate area and an ion transport connection area. Ions can migrate and be scheduled between multiple areas through a dynamic and controllable electric field, which is beneficial for partition isolation and noise reduction and improving the overall control fidelity. However, the multi-partition linkage leads to complex electrode wiring structure, increased difficulty in micro-nano fabrication and packaging, and the dynamic ion transport process may also introduce additional micro-motion noise. The threshold for system-level collaborative measurement and control and operation and maintenance is high.

[0036] (4) Related technologies for surface acoustic wave (SAW) manipulation of charged particles: Existing SAW technology is mostly used in bulk acoustic devices, electronic filtering, sensing and microfluidics. For example, Shilton et al. used SAW to realize single electron transport in two-dimensional electron gas, and a series of technologies using SAW for cell manipulation and droplet / particle acoustic suspension. These works mainly focus on the mechanical effects of SAW in condensed matter systems or macroscopic fluids, and do not involve the application of SAW directly inducing radio frequency fields through piezoelectric effect for ion radial pseudopotential confinement.

[0037] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] like Figure 1 As shown, this embodiment provides an ion trap chip, including: a piezoelectric substrate 100;

[0040] A surface acoustic wave excitation unit 200 is disposed on the piezoelectric substrate 100 and is configured to form a two-dimensional surface acoustic wave sound field composed of at least two independent and controllable surface acoustic wave components in the central region 300 of the piezoelectric substrate 100 when receiving an alternating drive signal.

[0041] The two-dimensional surface acoustic wave sound field generates a spatial periodic alternating electric field synchronized with the surface acoustic wave in the central region 300 through the piezoelectric effect of the piezoelectric substrate 100; the spatial periodic alternating electric field forms a pseudopotential for confining charged ions in a planar direction parallel to the upper surface of the piezoelectric substrate 100 under the time averaging of the sound field node positions within the oscillation period.

[0042] Among them, such as Figure 1 As shown, the surface acoustic wave (SAW) excitation unit 200 includes at least two pairs of oppositely arranged transducers. Each pair of transducers is located on opposite sides of the central region 300 and excites SAW waves propagating in opposite directions in different directions. The piezoelectric substrate 100, four sets of interdigital transducers, and their radio frequency drive connections allow the SAW waves to propagate from the periphery to the center and form a two-dimensional standing wave sound field in the central region of the chip.

[0043] The surface acoustic wave (SAW) excitation unit 200 includes at least two transducers and SAW reflectors respectively disposed opposite to the transducers. The at least two transducers excite SAW waves in different directions. The SAW waves excited by each transducer and the SAW waves reflected by the reflectors opposite to them are superimposed in the central region (300) to form a one-dimensional standing wave. The standing waves in different directions are superimposed to form the two-dimensional SAW sound field. The angle θ between the propagation directions of the SAW waves excited by the at least two pairs of transducers satisfies 0° < θ ≤ 90°. The transducers are straight interdigitated transducers, oblique interdigitated transducers, single-phase unidirectional transducers, spiral interdigitated transducers, or transduction devices based on photoacoustic effects.

[0044] In this embodiment, the piezoelectric substrate 100 is made of Y+128° cut lithium niobate (LiNbO3) wafers due to their high electromechanical coupling coefficient. It should be noted that this application is not limited to lithium niobate. The piezoelectric substrate 100 can be any material exhibiting a piezoelectric effect, including but not limited to:

[0045] 1) Piezoelectric single crystals: such as lithium tantalate (LiTaO3), quartz, Langasite, etc., have excellent temperature stability and low acoustic loss.

[0046] 2) Piezoelectric semiconductors: such as gallium arsenide (GaAs), gallium nitride (GaN), zinc oxide (ZnO), etc., which are easy to integrate with electronic or optoelectronic devices.

[0047] 3) Piezoelectric ceramics: such as lead zirconate titanate (PZT), which has an extremely high piezoelectric coefficient.

[0048] 4) Piezoelectric thin film structure: This involves depositing the aforementioned piezoelectric material thin film (such as AlN thin film) on a non-piezoelectric substrate (such as silicon or sapphire). This structure is advantageous for compatibility with CMOS processes.

[0049] Two pairs of orthogonal interdigital transducers (IDTs) are fabricated on a substrate surface using electron beam evaporation and stripping processes. The finger period p of the IDTs satisfies λ = n·p with respect to the wavelength λ of the surface acoustic wave to be excited. Each pair of IDTs consists of metal fingers (such as Ti / Au, typically 50–200 nm thick) with both finger width and finger spacing d. When an radio frequency signal with a frequency of f = v / p = v / (2d) (where v is the propagation speed of the surface acoustic wave on the substrate, typically about 3500–4000 m / s on lithium niobate) is applied, a surface acoustic wave with a wavelength of λ = 2d (corresponding to the fundamental frequency mode n = 1) is excited. In a typical implementation, the finger spacing d ranges from 0.1 to 10 μm, corresponding to a center operating frequency in the range of approximately 100 MHz to 10 GHz. The number of finger pairs in the IDT is typically 20 to 200, and the aperture is typically 50 to 500 μm to obtain sufficient surface acoustic wave power density in the central region. The typical RF drive power is 0.1 to 5 W, corresponding to an RF voltage amplitude at the input of the interdigital transducer in the range of tens to hundreds of volts. The SAW-induced potential amplitude A generated in the central region by the piezoelectric effect is typically in the range of 0.1 to 10 V, which, under appropriate parameters, can provide a potential well depth in the range of millielectron volts (meV) to electron volts (eV). Two pairs of orthogonal IDTs excite surface acoustic waves along the X and Y axes, respectively, and these waves meet and interfere in the central region. By adjusting the signal amplitude and phase of the relative IDT inputs, a stable two-dimensional standing wave is formed in the center. Due to the piezoelectric effect of lithium niobate, the strain field of a mechanical wave is accompanied by an electric potential field Φ(x,y,t) of the same frequency. The electric field is strongest at the antinodes of the standing wave and zero at the nodes. Charged ions in a rapidly alternating non-uniform electric field are subjected to a mean ponderomotive force and are pushed toward the minimum point of the electric field intensity (i.e., the standing wave node), thus being trapped in the XY plane.

[0050] Example 2: Axial Trapping and End Electrodes To achieve three-dimensional trapping, a restraining force needs to be applied in the Z-axis direction perpendicular to the chip surface. This example adds an end electrode assembly 400 to Example 1.

[0051] like Figure 1a As shown, the end electrode assembly 400 uses plate-shaped electrodes, which are respectively disposed above and below the piezoelectric substrate 100. By applying Vdc1 to the upper electrode and Vdc2 to the lower electrode (the voltage values ​​are independently adjustable), a confining electric field along the Z-axis is formed in the central region. Combined with the radial pseudopotential confinement provided by surface acoustic waves, three-dimensional confinement of the ion array is achieved.

[0052] like Figure 1b As shown, the end electrode assembly 400 employs needle-shaped electrodes with the tips positioned opposite each other above and below the piezoelectric substrate 100. The needle-shaped electrodes have a small tip curvature radius, which can generate a stronger local electric field gradient near the tip. Axial confinement is provided by independently adjustable DC voltages Vdc1 and Vdc2, while the tip structure causes minimal obstruction of the optical path, making it suitable for applications requiring a stronger local electric field gradient.

[0053] Example 3: Dynamic Addressing and Transport. Building upon Example 1, controlled movement of two-dimensional standing wave nodes in a plane is achieved by adjusting the frequency, amplitude, and phase of the radio frequency drive signal. This changes the depth, position, or shape of the potential wells, thereby enabling ion addressing and transport within the two-dimensional array. The input signals of the relatively positioned interdigital transducers have an adjustable phase difference. Changing the phase difference causes the standing wave nodes to shift along a predetermined direction. By fine-tuning the drive frequency to change the surface acoustic wave wavelength, the spacing between potential well nodes can be altered to adapt to different array layout requirements.

[0054] Example 4: Surface Acoustic Wave Reflector Structure:

[0055] Single-sided excitation + SAW reflector. Only one IDT is placed in a certain direction in the central region, and a micro / nano-fabricated metal strip / groove Bragg chord is used as a reflector on the corresponding side, causing coherent reflection of the unidirectional propagating surface acoustic wave to form a standing wave. Compared to a dual-sided dual IDT scheme, this configuration halves the electrical connection path, which is beneficial for chip and integrated packaging.

[0056] Example 5: Ion loading and initial cooling:

[0057] This embodiment describes the ion loading and cooling of the ion trap chip from Embodiment 1 within a vacuum chamber. 40 Ca + Taking ions as an example:

[0058] (5a) Vacuum environment. The ion trap chip is placed in a vacuum environment with a background vacuum level better than 10. -10Within the mbar ultra-high vacuum chamber, the chamber is equipped with optical windows for laser introduction and fluorescence collection.

[0059] (5b) Atomic beam source. A neutral calcium atom evaporation source is set at a distance of approximately 20-50 mm from the center region (300) of the ion trap chip. A collimated calcium atom beam is generated by a resistance-heated calcium furnace or a laser ablation target. The direction of the atom beam is limited by a collimation aperture to avoid contamination of the piezoelectric substrate (100) surface and the interdigital transducer (200). Optionally, a controllable mechanical shutter is set between the chip and the atomic beam source to control the loading time.

[0060] (5c) Two-step photoionization. A laser is incident from the optical window onto the central region (300), and calcium atoms are excited to 4s4p using a 423nm resonant laser. 1 The P1 state is further ionized using a 375nm or 390nm laser to ionize the calcium atoms in the excited state. 40 Ca + The ionized ions are directly captured by the pseudopotential minimum. The periodic array distribution of the pseudopotential minimum (well sites) is as follows: Figure 2 As shown.

[0061] (5d) Doppler cooling. After applying an alternating drive signal to the surface acoustic wave excitation unit (200) to form a stable pseudopotential well, a 397nm cooling laser (and S) is applied to the trapped ions. 1 / 2 -P 1 / 2 (transition red detuning) and 866nm repump laser (clear D) 3 / 2 (Dark state). The cooling laser has non-zero projections along all principal axes of the pseudopotential well, achieving simultaneous radial and axial cooling. In a typical implementation, after Doppler cooling for several milliseconds to tens of milliseconds, the ion temperature can be reduced to the order of approximately 0.5-1 mK, corresponding to a spatial scale of approximately... (where ω) sec The radial secular frequency of the pseudopotential well is much smaller than the ground state wave packet scale λ / (2π).

[0062] (5e) Further cooling. Based on Doppler cooling, an analytical sideband cooling scheme is adopted, using a 729nm narrow linewidth laser to drive S 1 / 2 →D 5 / 2 Blue sideband transitions, combined with 854nm pumping, cool the ion motion mode to the phonon number. Entering the ground state of motion to meet the requirements of improved quantum gate fidelity and quantum precision measurement.

[0063] (5f) Expansion of ion species. Except 40 Ca + In addition, the loading and cooling process of this embodiment is also applicable to 43 Ca +, 88 Sr + , 138 Ba + , 171 Yb + , 27 Al + / 40 Ca + For co-cooled plasma species, only the corresponding photoionization laser wavelength and cooling laser wavelength need to be changed.

[0064] Example 6: Typical Application Scenarios:

[0065] This embodiment describes typical applications of the planar ion trap chip or ion trap system of this application in different quantum devices.

[0066] (6a) Quantum computing and quantum gate operations. The two-dimensional pseudopotential array of this application is naturally adapted to large-scale two-dimensional qubit arrays: each well corresponds to one... 40 Ca + or 171 Yb + Ion qubits, single-qubit gates realize S at node locations through focused lasers. Rabi oscillations of D or hyperfine transitions; two-bit gates can be used. The scheme or the Cirac-Zoller scheme is implemented on the shared motion modes of adjacent well sites. Utilizing the dynamic control capability described in Example 3, two physically adjacent ions can be transported to the same pair of motion modes on demand to implement entanglement gates, avoiding the additional heating and reordering overhead introduced by the ion physical transport process in traditional QCCD schemes.

[0067] (6b) Atomic clocks and quantum frequency standards. This embodiment uses... 27 Al + / 40 Ca + Quantum logic co-cooling scheme: 40 Ca + Ions, acting as logical ions, provide laser cooling and readout. 27 Al + As clock ions 1 S0→ 3 The P0 clock transition provides an ultra-narrow linewidth. Through the dynamic addressing described in Example 3, multiple Al / Ca ion pairs can be sequentially transported to the readout region, enabling multi-ion parallel clock interrogation. Under quantum projection noise constraints, parallel interrogation of N ions can improve clock stability by approximately [percentage missing]. The design, which eliminates metal electrodes in the central region, significantly reduces ion heating and energy level shifting caused by surface charge noise, thus improving the clock system uncertainty to 10^5. -19 Magnitude.

[0068] (6c) Quantum Simulator. Using the two-dimensional pseudopotential array of this application, one ion is trapped in each well and interacts with its nearest-neighbor dipole-dipole through a shared motion mode, constructing a transverse-field Ising model, a Heisenberg model, or a geometrically frustrated quantum spin system. Through phase modulation in Example 3, the spacing between adjacent wells can be continuously adjusted, thereby continuously adjusting the spin-spin coupling strength to achieve adiabatic quantum simulation.

[0069] (6d) Quantum Sensor. This embodiment utilizes the high optical accessibility and tunable well depth of pseudopotential wells to apply this application to electric field sensing, magnetic field sensing, and gravity gradient sensing. For example: a single 40 Ca + ions or 171 Yb + Ions are trapped in a trap, and by monitoring the internal state coherence (Ramsey interference) or the frequency drift of the motion mode, information on the external alternating electric field intensity, magnetic field intensity, or local gravitational gradient can be extracted, respectively. Since the ions are suspended above the substrate surface and are not covered by metal electrodes, this application has the advantages of low background, wide bandwidth, and high spatial resolution in electromagnetic field sensing in the DC to GHz range.

[0070] Example 7

[0071] This embodiment provides an ion trap system based on the aforementioned ion trap chip, comprising:

[0072] A radio frequency drive source, electrically connected to the surface acoustic wave excitation unit 200, is used to provide an alternating drive signal;

[0073] A DC or quasi-static power supply, electrically connected to the end electrode assembly 400, is used to provide an axial limiting voltage;

[0074] A vacuum chamber, inside which the planar ion trap chip is placed.

[0075] The radio frequency drive source is configured to independently adjust the frequency, amplitude, and phase of the alternating drive signal applied to each channel of the surface acoustic wave (SAW) excitation unit 200, thereby dynamically adjusting the position, spacing, and pseudopotential depth of the two-dimensional SAW sound field nodes. The pseudopotential U induced by the SAW two-dimensional standing wave... pseudo The simulated cloud map of (x,y) is as follows: Figure 4 As shown in (a) above, its three-dimensional pseudopotential surface plot is as follows: Figure 4 As shown in (b) in the figure,

[0076] like Figure 3As shown, the SAW ion trap chip and peripheral functional modules located in the ultra-high vacuum chamber (UHV) include: a radio frequency drive source (multi-channel adjustable, electrically connected to the interdigital transducer), a DC or quasi-static power supply electrically connected to the end electrode assembly 400 to provide axial bias, a timing and control unit (FPGA / DAC, for unified scheduling of RF and DC channels), a laser system (providing cooling, control, and readout of the laser), a photon detection unit (PMT / EMCCD, for fluorescence collection), and a data acquisition and analysis unit.

[0077] Example 8

[0078] This embodiment provides an ion trapping method based on the ion trap chip, including:

[0079] S1. Load charged ions into the central region 300 in a vacuum environment;

[0080] S2. An alternating driving signal is applied to the surface acoustic wave excitation unit 200, so that the surface acoustic wave excitation unit 200 forms a two-dimensional surface acoustic wave sound field in the central region 300, which is composed of at least two independent and controllable surface acoustic wave components.

[0081] S3. The two-dimensional surface acoustic wave sound field is induced by the piezoelectric effect to generate a spatial periodic alternating electric field, forming a two-dimensional pseudopotential minimum point at the sound field node position under the time average within the oscillation period, thus confining the charged ions at the pseudopotential minimum point.

[0082] S4. An axial confinement electric field is applied through the terminal electrode assembly 400, and the three-dimensional trapping of charged ions is achieved in conjunction with the pseudopotential minimum point.

[0083] This includes, after executing S4:

[0084] S5: The loaded charged ions are cooled by laser to reach the Doppler cooling limit temperature or the ground state; the laser cooling includes Doppler cooling, polarization gradient cooling and analytical sideband cooling.

[0085] Example 9

[0086] This embodiment provides a quantum device, including the aforementioned ion trap chip or ion trap system; the quantum device is a quantum computer, a quantum simulator, an atomic clock, a quantum frequency standard, or a quantum sensor.

[0087] In summary, this application has the following beneficial effects:

[0088] 1) High optical accessibility: By utilizing the surface acoustic wave-induced electric field, there is no need to arrange dense metal electrodes in the central region, which significantly reduces the metal coverage and provides an excellent optical window for laser cooling, state preparation and fluorescence collection.

[0089] 2) Dynamically adjustable and addressable: By adjusting the frequency, phase and amplitude of the radio frequency signal loaded on the interdigital transducer, the node position and potential well depth of the standing wave can be dynamically changed, thereby achieving precise transport and addressing of ions, which is difficult to achieve with traditional static electrode ion traps.

[0090] 3) Easy to expand and integrate: Surface acoustic wave technology is a mature micro-nano fabrication technology that makes it easy to fabricate arrayed ion traps on large-area substrates to achieve high-density scalable quantum bit arrays.

[0091] 4) Low noise: The simplified electrode structure helps reduce the heating rate caused by surface roughness or adsorption on the electrode.

[0092] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An ion trap chip, characterized in that, include: Piezoelectric substrate (100); A surface acoustic wave excitation unit (200) is disposed on the piezoelectric substrate (100) and is configured to form a two-dimensional surface acoustic wave sound field in the central region (300) of the piezoelectric substrate (100) when receiving an alternating drive signal. The field is composed of at least two independently controllable surface acoustic wave components. The two-dimensional surface acoustic wave sound field generates a spatial periodic alternating electric field synchronized with the surface acoustic wave in the central region (300) through the piezoelectric effect of the piezoelectric substrate (100). The spatial periodic alternating electric field, under the time averaging of the acoustic field node positions within the oscillation period, forms a pseudopotential for confining charged ions in a planar direction parallel to the upper surface of the piezoelectric substrate (100).

2. The ion trap chip according to claim 1, characterized in that, The surface acoustic wave excitation unit (200) includes at least two pairs of transducers arranged opposite each other. Each pair of transducers is located on opposite sides of the central region (300) and excites surface acoustic waves propagating in opposite directions in different directions.

3. An ion trap chip according to claim 2, characterized in that, The surface acoustic wave excitation unit (200) includes at least two transducers and surface acoustic wave reflectors respectively arranged opposite to the transducers. The at least two transducers excite surface acoustic waves in different directions. The surface acoustic waves excited by each transducer and the surface acoustic waves reflected by the reflector opposite to them are superimposed in the central region (300) to form a one-dimensional standing wave. The standing waves in different directions are superimposed to form the two-dimensional surface acoustic wave sound field. The angle θ between the propagation directions of the surface acoustic waves excited by the at least two pairs of transducers satisfies 0° < θ ≤ 90°.

4. An ion trap chip according to claim 3, characterized in that, Also includes: The terminal electrode assembly (400) is used to apply a DC or quasi-static voltage to provide an axial confinement electric field, which, in conjunction with the pseudopotential minimum, enables three-dimensional trapping of ions. The end electrode assembly (400) is disposed at least at one location on the upper surface, lower surface, side surface, interior or exterior space of the piezoelectric substrate (100); the end electrode assembly (400) is a planar electrode disposed on the surface of the piezoelectric substrate, a partitioned planar electrode disposed on the surface of the piezoelectric substrate, or a three-dimensional needle tip structure disposed above or below the piezoelectric substrate.

5. An ion trap chip according to claim 4, characterized in that, The piezoelectric substrate (100) is composed of one or more of the following materials: piezoelectric single crystal, piezoelectric ceramic, piezoelectric semiconductor, piezoelectric thin film, or heterostructure of the above materials.

6. An ion trap chip according to claim 5, characterized in that, The material of the piezoelectric substrate (100) is selected from one or more combinations of lithium niobate, lithium tantalate, aluminum nitride, scandium-doped aluminum nitride, zinc oxide, quartz crystal, gallium arsenide, gallium nitride, lead zirconate titanate, and langasate.

7. An ion trap chip according to claim 6, characterized in that, The transducer is a straight interdigital transducer, an oblique interdigital transducer, a single-phase unidirectional transducer, a spiral interdigital transducer, or a transducer based on photoacoustic effect.

8. An ion trap system, based on an ion trap chip according to any one of claims 1-7, characterized in that, include: A radio frequency drive source is electrically connected to the surface acoustic wave excitation unit (200) to provide an alternating drive signal; A DC or quasi-static power supply, electrically connected to the terminal electrode assembly (400), is used to provide an axial limiting voltage; A vacuum chamber, inside which the planar ion trap chip is placed.

9. An ion trapping method based on an ion trap chip according to any one of claims 1-7, characterized in that, include: S1. Charged ions are loaded into the central region (300) under vacuum conditions; S2. Apply an alternating driving signal to the surface acoustic wave excitation unit (200) so that the surface acoustic wave excitation unit (200) forms a two-dimensional surface acoustic wave sound field in the central region (300) composed of at least two independent and controllable surface acoustic wave components. S3. The two-dimensional surface acoustic wave sound field is induced by the piezoelectric effect to generate a spatial periodic alternating electric field, forming a two-dimensional pseudopotential minimum point at the sound field node position under the time average within the oscillation period, thus confining the charged ions at the pseudopotential minimum point. S4. An axial confinement electric field is applied through the terminal electrode assembly (400), and the three-dimensional trapping of charged ions is achieved in conjunction with the pseudopotential minimum point.

10. A quantum device, characterized in that, Includes an ion trap chip as described in any one of claims 1-7 or an ion trap system as described in claim 8; the quantum device is a quantum computer, a quantum simulator, an atomic clock, a quantum frequency standard, or a quantum sensor.

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