High-fidelity rapid ion transport device and voltage optimization method

Abstract

The invention discloses a high-fidelity rapid ion transport device. The device comprises an upper computer module, an FPGA data processing module, a digital-analog voltage conversion module, a voltage amplification module, a low-pass filtering module and an ion trap module which are connected in sequence, the invention also discloses a voltage optimization method for high-fidelity rapid ion transport, the speed of ion movement is controlled through a sin2 function, and the method provided by the invention calculates the optimal voltage value of each transport electrode under the transport track of ions through a quadratic programming algorithm; the moving process of ions has the characteristics of slow start, constant-speed middle section and slow stop, and the smooth movement can effectively avoid excitation of a motion mode and reduce the heating effect; the optimal voltage value of each transport electrode avoids additional heating, improves the efficiency of quantum calculation, and meets the high fidelity requirement of the ion logic gate.

Description

Technical Field

[0001] This invention belongs to the technical field of ion trap quantum computing systems, specifically relating to a device for high-fidelity rapid ion transport and a voltage optimization method for high-fidelity rapid ion transport. Background Technology

[0002] In recent years, quantum computing has gained widespread attention due to the development of quantum information science and technology. Currently, ion trap systems are among the most promising physical systems for realizing quantum computing. Within these systems, the QCCD (quantum charge-coupled device) scheme, also known as the ion transport scheme, is one of the more mainstream large-scale general-purpose quantum computing schemes. In the QCCD scheme, the ion trap is configured with multiple spatial regions for operations such as logic gates, qubit storage, and quantum state measurement. Large-scale general-purpose quantum computing is achieved through the combination of these operations. To realize the QCCD scheme, devices and methods for fast and accurate ion transport in the ion trap system are essential. Simultaneously, the ion trap electrodes need to be precisely designed and fabricated, and their electrode voltages need to be precisely controlled to accurately control the ion transport path. High-response control circuits are also required to improve ion transport speed and quantum computing efficiency, while avoiding significant heating of ion vibrations to ensure the fidelity of quantum logic gates. In summary, fast and accurate ion transport is crucial for large-scale general-purpose quantum computing using ion trap systems.

[0003] Currently, the devices that enable rapid ion transport in ion trap systems are mainly based on digital-to-analog converter (DAC) systems. However, traditional DACs have a small output range, which cannot meet the requirement of a large voltage conversion range for ion transport. They also lack corresponding voltage optimization algorithms. During rapid ion transport, they may heat the ions and reduce the fidelity of the quantum logic gates. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by providing a device for high-fidelity rapid ion transport and a voltage optimization method for high-fidelity rapid ion transport.

[0005] The above-mentioned objectives of the present invention are achieved by the following technical means:

[0006] A voltage optimization method for high-fidelity rapid ion transport includes the following steps:

[0007] Step 1: Divide the ion transport process into N steps and determine the ion transport trajectory, where k is the sequence number of the ion transport step, and k ranges from 0 to N.

[0008] Step 2: Define the local potential optimization range and obtain the axial local trapping potential field f required for the local potential optimization range during the k-th step ion transport. k ;

[0009] Step 3: Calculate the potential generated at position z when a unit voltage is applied to the i-th transport electrode of the ion trap, where i is the index of the transport electrode, i∈(imin,…,imax), imin and imax are the minimum and maximum values ​​of index i, respectively, and z is the axial position coordinate.

[0010] Step 4: Calculate the potential matrix v in the local potential optimization range when a unit voltage is applied to each transport electrode of the ion trap during the k-th transport step. k ;

[0011] Step 5: Set the objective function of the voltage optimization algorithm for the k-th transport step, and solve for the voltage of each transport electrode of the ion trap for the k-th transport step;

[0012] Step 6: Based on the ion transport trajectory, repeat steps 2 to 5 in sequence to obtain the voltage of each transport electrode of the ion trap in each transport step.

[0013] As described above, the objective function of the voltage optimization algorithm for the k-th transport step in step 5 is based on the following formula:

[0014]

[0015] In the formula, d k Let be the vector of voltage values ​​of each transport electrode in the ion trap during the k-th ion transport step. For d k The transpose of , V imin V represents the voltage value of the transport electrode with serial number i and index imin. imax Q represents the voltage value of the transport electrode with index i and value imax. k Let c be the coefficient matrix of the quadratic term of the objective function for ion transport in the k-th step. k Let be the coefficient vector of the first-order term during the k-th step of ion transport. For c k The transpose of ;

[0016] Q of ion transport in step k k and c k They are respectively:

[0017]

[0018]

[0019] In the formula, For v kThe transpose of the matrix, f k The transpose of .

[0020] The transport trajectory of the ions in step 1 as described above is based on the following formula:

[0021]

[0022] In the formula, z0 is the initial position of the ion in the axial direction, z N z represents the position in the axial direction after the Nth step of ion transport. k This represents the position of the ion in the axial direction after the k-th step of ion transport.

[0023] As described above, the local potential optimization range in step 2 is (z min ,z max The calculation is based on the following formula:

[0024]

[0025] In the formula, L is the buffer length of the set local potential optimization interval, and z min and z max These are the two boundaries of the local potential optimization interval;

[0026] The axial local trapping potential field f required for the local potential optimization range during the k-th step of ion transport in step 2. k for:

[0027] f k =(Φ k (z min ),…,Φ k (z max ))

[0028] In the formula, Φ k (z) represents the axial local trapping potential at position z during the k-th ion transport, Φ k (z min For the k-th step of transport, z is taken at z. min The axial local trapping potential at the position of time, Φ k (z max For the k-th step of transport, z is taken at z. max The axial local trapping potential at the position of time.

[0029] As described above, the axial local trapping potential Φ at position z during the k-th step of ion transport. k (z) is calculated based on the following formula:

[0030]

[0031] In the formula, m is the mass of the transported ion, and ωz denoted as the macroscopic motion frequency in the axial direction, and e as the charged quantity of the transported ions.

[0032] As described above, in step 3, the basis functions are used. The potential generated at position z when a unit voltage is applied to the i-th transport electrode is calculated as follows:

[0033]

[0034] In the formula, (x i,2 ,0,z i,2 ) and (x i,1 ,0,z i,1 ) represents one pair of diagonal coordinates of the i-th transport electrode of the rectangle of the ion trap, and each transport electrode selects a pair of diagonals in the same direction; x is the radial position coordinate, and y is the position coordinate in a direction that is perpendicular to both the axial and radial directions.

[0035] As described above, in step 4, during the k-th transport phase, the potential matrix v is the potential matrix within the local potential optimization range when a unit voltage is applied to each transport electrode of the ion trap. k Based on the following formula:

[0036]

[0037] In the formula, and When a unit voltage is applied to the transport electrode with serial number i and minimum value imin, the values ​​at z are respectively... min Position and z max The electric potential generated at that location, and When a unit voltage is applied to the transport electrode where the index i is the maximum value imax, the z min Position and z max The electric potential generated at the location.

[0038] As mentioned above, when performing rapid transport of multi-ion chains, the value of L is increased.

[0039] A device for high-fidelity rapid ion transport includes an ion trap module, and further includes a host computer module, an FPGA data processing module, a digital-to-analog voltage conversion module, a voltage amplification module, and a low-pass filter module connected in sequence.

[0040] The host computer module includes an algorithm module and a human-computer interaction interface. The algorithm module is used to optimize the buffer length L of the local potential optimization interval and the macro motion frequency ω in the axial direction. zCalculate the voltage values ​​of each transport electrode in the ion trap during each transport step; the human-machine interface is used to manually set and display the buffer length L of the local potential optimization interval and the macro-motion frequency ω in the axial direction. z It is also used to manually set the voltage of the center electrode, each cap electrode, and each transport electrode of the ion trap module; the host computer module also transmits the voltage control commands of each transport electrode to the FPGA data processing module.

[0041] The FPGA data processing module is used to receive voltage control commands sent by the host computer module and quickly convert the voltage control commands into commands that can be read by the digital-to-analog voltage conversion module.

[0042] The digital-to-analog voltage conversion module is used to convert the digital signals sent by the FPGA data processing module into continuous analog voltages and send the analog voltages to the voltage amplification module.

[0043] The voltage amplification module is used to proportionally amplify the received analog voltage and send the amplified analog voltage to the low-pass filter module.

[0044] The low-pass filter module is used to filter out noise from the amplified analog voltage to obtain the voltage values ​​of each transport electrode;

[0045] The ion trap module is used to trap and transport ions and receives the voltage values ​​of each transport electrode.

[0046] Compared with the prior art, the present invention has the following advantages:

[0047] (1) The method of the present invention uses sin 2 The function controls the speed of ion movement, and the movement process has the characteristics of slow start, uniform speed in the middle, and slow stop. This smooth movement can effectively avoid the excitation of motion modes and reduce the heating effect.

[0048] (2) The method of the present invention calculates the optimal voltage values ​​of each transport electrode under the transport trajectory of ions using a quadratic programming algorithm, avoiding additional heating, improving the efficiency of quantum computing, and meeting the high fidelity requirements of ion logic gates.

[0049] (3) The device of the present invention also expands the voltage output range by adding a voltage amplification module and a low-pass filter module. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the device of the present invention;

[0051] Figure 2 This is a schematic diagram of the human-computer interaction interface of the host computer module of the present invention;

[0052] Figure 3This is a plan view of the ion trap according to Embodiment 1 of the present invention;

[0053] Figure 4 This is a schematic diagram of the signal transmission between the FPGA data processing module and the digital-to-analog voltage conversion module of the present invention;

[0054] Figure 5 This is a schematic diagram showing the voltage changes of each transport electrode in the ion trap during rapid ion transport according to the present invention.

[0055] Figure 6 This is a schematic diagram illustrating the change of the local trapping potential field along the axis in Embodiment 1 of the present invention;

[0056] Figure 7 This is a schematic diagram illustrating the positional changes of ions in Example 1 of the present invention;

[0057] Figure labels and corresponding component names:

[0058] 1-First cap electrode; 2-First transport electrode; 3-Second transport electrode; 4-Third transport electrode; 5-Fourth transport electrode; 6-Fifth transport electrode; 7-Second cap electrode; 8-Third cap electrode; 9-Sixth transport electrode; 10-Seventh transport electrode; 11-Eighth transport electrode; 12-Ninth transport electrode; 13-Tenth transport electrode; 14-Fourth cap electrode; 15-First radio frequency electrode; 16-Center electrode; 17-Second radio frequency electrode; 18-Ion trapping region; 19-Quantum information processing region. Detailed Implementation

[0059] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to embodiments. The embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0060] Example 1:

[0061] A voltage optimization method for high-fidelity rapid ion transport includes the following steps:

[0062] The three-dimensional directions of the ion trap are defined as the axial direction, the radial direction, and the direction that is perpendicular to both the axial and radial directions, respectively; the axial direction is the gradient direction of the trapping potential field provided by the cap electrode of the ion trap; the radial direction is the gradient direction of the trapping potential field provided by the radio frequency electrode of the ion trap; the axial position coordinates are denoted as z, the radial position coordinates are denoted as x, and the position coordinates of the direction that is perpendicular to both the axial and radial directions are denoted as y.

[0063] In this embodiment, the ion trap electrodes include a central electrode 16, four cap electrodes, two radio frequency electrodes, and ten transport electrodes. The four cap electrodes include a first cap electrode 1, a second cap electrode 7, a third cap electrode 8, and a fourth cap electrode 14, used to provide a global trapping potential field along the axis. The ten transport electrodes include a first transport electrode 2, a second transport electrode 3, a third transport electrode 4, a fourth transport electrode 5, a fifth transport electrode 6, a sixth transport electrode 13, a seventh transport electrode 12, an eighth transport electrode 11, a ninth transport electrode 10, and a tenth transport electrode 9, used to provide a local trapping potential field along the axis. The two radio frequency electrodes include a first radio frequency electrode 15 and a second radio frequency electrode 17, used to provide a global trapping potential field along the axis. To provide a radial trapping potential field; to provide an axial local trapping potential field to transport ions by adjusting the voltage of each transport electrode, the voltages on the central electrode 16, each cap electrode, and each radio frequency electrode remain unchanged; since the voltage values ​​of the first transport electrode 2, the second transport electrode 3, the third transport electrode 4, the fourth transport electrode 5, and the fifth transport electrode 6 are the same as those of the sixth transport electrode 13, the seventh transport electrode 12, the eighth transport electrode 11, the ninth transport electrode 10, and the tenth transport electrode 9, which are respectively opposite to them, in this embodiment only the voltage values ​​of the first transport electrode 2, the second transport electrode 3, the third transport electrode 4, the fourth transport electrode 5, and the fifth transport electrode 6 need to be solved.

[0064] Step 1: Determine the ion transport trajectory. Specifically, divide the transport process into N steps, and denote the z-position after the k-th ion transport as z. k The value range of the index k is: 0≤k≤N. Then the position z in the z-direction after the k-th step of ion transport is... k Calculated based on the following formula:

[0065]

[0066] In the formula, z0 is the initial position of the ion in the axial direction, z N z represents the position in the axial direction after the Nth step of ion transport. k This refers to the axial position of the ion after the k-th step of ion transport; this invention utilizes sin 2 The function controls the speed of ion movement, and the movement process has the characteristics of slow start, uniform speed in the middle, and slow stop. This smooth movement can effectively avoid exciting motion modes and reduce heating effects. Ion position changes are as follows: Figure 7 As shown.

[0067] Step 2: Define the local potential optimization range and obtain the axial local trapping potential field required for the local potential optimization range of each transport step. This includes the following steps:

[0068] Step 2.1: Set the buffer length L of the local potential optimization interval, then define the local potential optimization interval as (z min,z max Based on the following formula:

[0069]

[0070] In this embodiment, the buffer length L of the local potential optimization region is 40 μm. For rapid transport of multi-ion chains (L can be increased to 60 μm when there are two ions), the value of L can be increased.

[0071] Step 2.2: Calculate the axial local trapping potential field f required for the local potential optimization range during the k-th step ion transport. k :

[0072] f k =(Φ k (z min ),…,Φ k (z max (3)

[0073] In the formula, Φ k (z) represents the axial local trapping potential at position z during the k-th ion transport, Φ k (z min For the k-th step of transport, z is taken at z. min The axial local trapping potential at the position of time, Φ k (z max For the k-th step of transport, z is taken at z. max The localized trapping potential along the axis at the position of time;

[0074] The axial local trapping potential Φ at position z during the k-th step of ion transport. k (z) is calculated based on the following formula:

[0075]

[0076] In the formula, m is the mass of the transported ion, and ω z denoted as the macroscopic motion frequency in the axial direction, and e as the charged quantity of the transported ions.

[0077] Step 3: Calculate the potential generated at position z when a unit voltage is applied to the i-th transport electrode, using the basis function φ. basei (z) is used to define i∈(2,3,4,5,6) in this embodiment. basei (z) can be defined as:

[0078]

[0079] In the formula, (x i,2 ,0,z i,2 ) and (x i,1 ,0,z i,1Let be a pair of diagonal coordinates of the i-th transport electrode of the rectangle of the ion trap, and each transport electrode is selected from a pair of diagonals in the same direction; i is the index of the transport electrode, i∈(imin,…,imax), where imin and imax are the minimum and maximum values ​​of index i, respectively.

[0080] In this example, the cap electrode is 1550 μm long and 700 μm wide; the RF electrode is 5020 μm long and 600 μm wide; the center electrode 16 is 5020 μm long and 600 μm wide; the RF electrode is spaced 50 μm from the center electrode 16, 50 μm from the transport electrode, and 20 μm from each transport electrode; in this embodiment, using... Figure 3 With the center of the ion capture region 19 as the origin, the diagonal coordinates (z, y, x) of the first transport electrode 2 are (-1070, 0, 2550) and (-370, 0, 1000), respectively; the diagonal coordinates of the second transport electrode 3 are (-350, 0, 2550) and (350, 0, 1000), respectively; the diagonal coordinates of the third transport electrode 4 are (370, 0, 2550) and (1070, 0, 1000), respectively; and the diagonal coordinates of the fourth transport electrode 5 are (1090, 0, 2550) and (1790), respectively. The diagonal coordinates of the fifth transport electrode 6 are (1810, 0, 2550) and (2510, 0, 1000); the value of y is 500 μm. The voltages of other electrodes remain unchanged and are not included in the calculation. The trapped ions are rapidly transported from the ion trapping region 18 to the center of the quantum information processing region 19. The ion coordinates change from the origin (0, 500, 0) to (0, 500, 1440), and the transport distance is 1440 μm. Based on the above parameters, the potential generated at the z position when a unit voltage is applied to each transport electrode can be calculated.

[0081] Step 4: Calculate the potential matrix v in the local potential optimization range when a unit voltage is applied to each transport electrode (first transport electrode 2, second transport electrode 3, third transport electrode 4, fourth transport electrode 5, and fifth transport electrode 6) of the ion trap during the k-th step of ion transport. k Calculated based on the following formula:

[0082]

[0083] In the formula, and When a unit voltage is applied to the first transport electrode 2, the z values ​​are respectively... min Position and z max The electric potential generated at that location, and When a unit voltage is applied to the fifth transport electrode 6, the z values ​​are respectively... min Position and zmax The electric potential generated at the location.

[0084] Step 5: Define the objective function of the voltage optimization algorithm for ion transport in step k. Minimize the objective function for ion transport in step k using a quadratic programming algorithm to obtain the voltage values ​​of each transport electrode of the ion trap in step k. The objective function of the voltage optimization algorithm for ion transport in step k is defined as follows:

[0085]

[0086] In the formula, d k Let be the vector of voltage values ​​of each transport electrode in the ion trap during the k-th ion transport step, i.e., with optimization variables. For d k The transpose of , In this embodiment, Wherein, V2, V3, V4, V5, and V6 are the voltage values ​​of the first transport electrode 2, the second transport electrode 3, the third transport electrode 4, the fourth transport electrode 5, and the fifth transport electrode 6, respectively; Q k Let c be the quadratic coefficient matrix of the objective function of the voltage optimization algorithm for ion transport in the k-th step. k Let be the coefficient vector of the first-order term of the objective function of the voltage optimization algorithm for ion transport at step k. For c k The transpose of ;

[0087] Q of ion transport in step k k and c k They are respectively:

[0088]

[0089]

[0090] in, The potential matrix v k The transpose of the matrix, The local confinement potential field f along the axis k The transpose of .

[0091] Furthermore, since the digital-to-analog voltage conversion module has a maximum output range (the maximum output range in this embodiment is ±80V, so the full-scale range FSR = 160), constraints need to be applied to the voltage of each transport electrode, based on the following formula:

[0092] Gd k ≤h (10)

[0093] in:

[0094]

[0095] Where G is the constraint coefficient matrix and h is the constraint constant term, the size of which is determined by the full-scale range FSR.

[0096] Step 6: Based on the ion transport trajectory, repeat steps 2-5 sequentially, calculating the macro-motion frequency ω in the axial direction for each repetition. z The quadratic coefficient matrix Q of the objective function of the voltage optimization algorithm for the k-th step ion transport under the buffer length L of the local potential optimization interval. k The coefficient vector c of the first-order term of the objective function of the voltage optimization algorithm for ion transport at step k is... k Q k and c k By substituting the objective function of the voltage optimization algorithm into the k-th step of ion transport, and using quadratic programming algorithms such as the Lagrange method, we can solve for the voltage combinations in each step and obtain the voltage of each transport electrode of the ion trap in each transport step.

[0097] In the process of rapid ion transport, the voltage signal is sent to the corresponding electrode through the rapid ion transport control device, which can achieve the requirement of high-fidelity rapid ion transport.

[0098] Example 2:

[0099] like Figure 1 As shown, a device for high-fidelity rapid ion transport includes a host computer module, an FPGA data processing module, a digital-to-analog voltage conversion module, a voltage amplification module, a low-pass filter module, and an ion trap module connected in sequence.

[0100] The host computer module includes an algorithm module and a human-computer interaction interface. The algorithm module is used to optimize the buffer length L of the local potential optimization range and the macro-motion frequency ω in the axial direction. z The voltage values ​​of each transport electrode in the ion trap during each transport step are calculated. In this embodiment, a quadratic programming algorithm is used. The human-computer interface is used to manually set and display the buffer length L of the local potential optimization interval and the macro-motion frequency ω in the axial direction. z The voltage of the center electrode 16, each cap electrode, and each transport electrode can also be manually set; the host computer module will also transmit the voltage control command of each transport electrode to the FPGA data processing module.

[0101] like Figure 2As shown, this embodiment provides a human-machine interface for the host computer module. The human-machine interface includes 15 voltage input windows, each of which can be independently controlled and used to compensate for the micro-movement of ions. The human-machine interface also includes a window for rapid transport, containing a buffer length L of the local potential optimization zone and a macro-motion frequency ω in the axial direction. z After clicking the start button, the algorithm module can use L and ω z Calculate the voltage required for rapid ion transport to ensure that ions can be transported to the target location with high fidelity.

[0102] The FPGA data processing module is used to receive voltage control commands sent by the host computer module and quickly convert the voltage control commands into commands that can be read by the digital-to-analog voltage conversion module, so as to achieve a fast voltage response with a response time on the order of nanoseconds.

[0103] The digital-to-analog voltage conversion module is used to convert the digital signals (binary code) sent by the FPGA data processing module into continuous analog voltages and send the analog voltages to the voltage amplification module. The maximum update rate of the digital-to-analog voltage conversion module needs to be greater than 16MUPS (Million Updates Per Second) and the maximum slew rate needs to be greater than 20V / μs.

[0104] The voltage amplification module is used to proportionally amplify the received analog voltage to achieve a larger voltage output range to meet the requirements of fast transmission; and sends the amplified analog voltage to the low-pass filter module.

[0105] The low-pass filter module is used to filter out high-frequency noise in the analog voltage, improve the stability of the analog voltage, and obtain the voltage values ​​of each transport electrode.

[0106] The ion trap module is used to trap ions and achieve rapid ion transport by receiving the voltage values ​​of each transport electrode.

[0107] like Figure 3As shown, the ion trap of this embodiment includes four cap electrodes (first cap electrode 1, second cap electrode 7, third cap electrode 8, and fourth cap electrode 14) providing a global trapping potential field in the radial direction; it also includes two radio frequency electrodes (first radio frequency electrode 15 and second radio frequency electrode 17) providing a radial trapping potential field in the axial direction; it also includes a center electrode 16 in the axial direction; and it also includes ten transport electrodes (first transport electrode 2, second transport electrode 3, third transport electrode 4, fourth transport electrode 5, and fourth transport electrode 6) providing a local trapping potential field in the radial direction to transport ions. Transport electrode 3, third transport electrode 4, fourth transport electrode 5, fifth transport electrode 6, sixth transport electrode 13, seventh transport electrode 12, eighth transport electrode 11, ninth transport electrode 10, and tenth transport electrode 9), wherein two radio frequency electrodes are symmetrically arranged on both sides of the central electrode 16, and the first transport electrode 2 and the sixth transport electrode 13, the second transport electrode 3 and the seventh transport electrode 12, the third transport electrode 4 and the eighth transport electrode 11, and the fifth transport electrode 6 and the tenth transport electrode 9 are respectively symmetrically arranged about the central electrode 16;

[0108] Since the voltage values ​​of the first transport electrode 2, the second transport electrode 3, the third transport electrode 4, the fourth transport electrode 5, and the fifth transport electrode 6 are the same as those of the sixth transport electrode 13, the seventh transport electrode 12, the eighth transport electrode 11, the ninth transport electrode 10, and the tenth transport electrode 9, respectively, it is only necessary to solve for the voltage values ​​of the first transport electrode 2, the second transport electrode 3, the third transport electrode 4, the fourth transport electrode 5, and the fifth transport electrode 6.

[0109] The voltage of the central electrode 16 remains constant during rapid ion transport. Region 18 is an ion trapping region used to confine ions ionized by atomic vapor ejected from the atomic furnace (not shown) within the ion trapping region 18. Region 19 is a quantum information processing region. Ions trapped in the ion trapping region 18 are rapidly transported to the quantum information processing region 19 for quantum measurement and other operations. Since the ion trapping region 18 may be contaminated by atomic vapor, rapidly transporting ions to the quantum information processing region 19 can effectively avoid the above problems.

[0110] When rapid ion transport is required, the host computer module optimizes the buffer length L of the local potential range and the macro-motion frequency ω in the axial direction. zThe required voltage for each transport electrode is calculated using a quadratic programming algorithm. The host computer module establishes a low-latency, high-efficiency transmission network with the FPGA data processing module, and then sends a control signal for the fast transport voltage. Upon receiving the voltage control signal, the FPGA data processing module decodes the signal into voltage data and chip select data at a processing speed on the order of 50ns, and sends the voltage data to the digital-to-analog voltage conversion module of the corresponding electrode. The digital-to-analog voltage conversion module converts the digital voltage control signal into a continuously changing analog voltage. The maximum update rate of the digital-to-analog voltage conversion module is 16MUPS, which can process up to 16 million voltage updates per second, and the maximum slew rate is greater than 20V / μs. The analog voltage is amplified tenfold by a voltage amplification module to expand the voltage output range. The amplified analog voltage then passes through a low-pass filter module to filter out high-frequency noise before being input to the ion trap electrode for adjusting ion position and fast ion transport.

[0111] As one possible implementation method, such as Figure 4 As shown, the host computer module sends a voltage control signal calculated by a quadratic programming algorithm, including the voltage value and a chip select signal. The chip select signal controls the voltage of the corresponding electrode. When the FPGA data processing module receives the voltage control signal, it decodes the signal into voltage data and chip select data, which are then sent to the digital-to-analog voltage conversion module. The digital-to-analog voltage conversion module converts the digital voltage data into an analog voltage and sends the analog voltage to the corresponding electrode selected by the chip select data. The specific parameters of the digital-to-analog voltage conversion module are: 16 output channels; 24-bit voltage resolution; maximum update rate of 16MUPS; and maximum slew rate of 20V / μs. Subsequently, the analog voltage is amplified by the amplifier circuit module and then sent to the low-pass filter circuit module to filter out high-frequency noise in the circuit. The voltage signal is then transmitted to the corresponding electrode to achieve high-fidelity rapid ion transport.

[0112] like Figure 5 As shown, to accurately control the ion transport path and improve the ion transport rate while avoiding significant ion heating, the voltage value of the fast transport electrode is optimized using a quadratic programming algorithm. For the ion trap system, fast ion transport only requires changing the static trapping potential. Only when the static trapping potential remains constant or changes very little during transport can the fast ion transport meet the requirements of the QCCD scheme. Therefore, during the fast ion transport operation, the static trapping potential is kept as constant as possible at each step, resulting in a corresponding macro-motion frequency ω in the axial direction. z Remain unchanged.

[0113] It should be noted that the embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A voltage optimization method for high-fidelity rapid ion transport, characterized in that, Includes the following steps: Step 1: Divide the ion transport process into N steps and determine the ion transport trajectory, where k is the sequence number of the ion transport step, and k ranges from 0 to N. Step 2: Define the local potential optimization range and obtain the axial local trapping potential field f required for the local potential optimization range during the k-th step of ion transport. k ; Step 3: Calculate the potential generated at position z when a unit voltage is applied to the i-th transport electrode of the ion trap, where i is the index of the transport electrode, i∈(imin,…,imax), imin and imax are the minimum and maximum values ​​of index i, respectively, and z is the axial position coordinate. Step 4: Calculate the potential matrix v in the local potential optimization range when a unit voltage is applied to each transport electrode of the ion trap during the k-th transport step. k ; Step 5: Set the objective function of the voltage optimization algorithm for the k-th transport step, and solve for the voltage of each transport electrode of the ion trap for the k-th transport step; Step 6: Based on the ion transport trajectory, repeat steps 2 to 5 in sequence to obtain the voltage of each transport electrode of the ion trap in each transport step.

2. The voltage optimization method for high-fidelity rapid ion transport according to claim 1, characterized in that, The objective function of the voltage optimization algorithm for the k-th transport step in step 5 is based on the following formula: In the formula, d k Let be the vector of voltage values ​​of each transport electrode in the ion trap during the k-th ion transport step. For d k The transpose of , V imin V represents the voltage value of the transport electrode with serial number i and index imin. imax Q represents the voltage value of the transport electrode with index i and value imax. k Let c be the coefficient matrix of the quadratic term of the objective function for ion transport in the k-th step. k Let be the coefficient vector of the first-order term during the k-th step of ion transport. For c k The transpose of ; Q of ion transport in step k k and c k They are respectively: In the formula, For v k The transpose of the matrix, f k The transpose of .

3. The voltage optimization method for high-fidelity rapid ion transport according to claim 2, characterized in that, The transport trajectory of the ions in step 1 is based on the following formula: In the formula, z0 is the initial position of the ion in the axial direction, z N z represents the position in the axial direction after the Nth step of ion transport. k This represents the position of the ion in the axial direction after the k-th step of ion transport.

4. The voltage optimization method for high-fidelity rapid ion transport according to claim 3, characterized in that, The local potential optimization range in step 2 is (z min ,z max The calculation is based on the following formula: In the formula, L is the buffer length of the set local potential optimization interval, and z min and z max These are the two boundaries of the local potential optimization interval; The axial local trapping potential field f required for the local potential optimization range during the k-th step of ion transport in step 2. k for: f k =(Φ k (z min ),…,Φ k (z max )) In the formula, Φ k (z) represents the axial local trapping potential at position z during the k-th ion transport, Φ k (z min For the k-th step of transport, z is taken at z. min The axial local trapping potential at the position of time, Φ k (z max For the k-th step of transport, z is taken at z. max The axial local trapping potential at the position of time.

5. The voltage optimization method for high-fidelity rapid ion transport according to claim 4, characterized in that, The axial local trapping potential Φ at position z during the k-th step ion transport. k (z) is calculated based on the following formula: In the formula, m is the mass of the transported ion, and ω z denoted as the macroscopic motion frequency in the axial direction, and e as the charged quantity of the transported ions.

6. The voltage optimization method for high-fidelity rapid ion transport according to claim 2, characterized in that, In step 3, the basis function is used. The potential generated at position z when a unit voltage is applied to the i-th transport electrode is calculated as follows: In the formula, (x i,2 ,0,z i,2 ) and (x i,1 ,0,z i,1 ) represents one pair of diagonal coordinates of the i-th transport electrode of the rectangle of the ion trap, and each transport electrode is selected with a pair of diagonals in the same direction; x is the radial position coordinate, and y is the position coordinate in a direction that is perpendicular to both the axial and radial directions.

7. The voltage optimization method for high-fidelity rapid ion transport according to claim 2, characterized in that, In step 4, during the k-th transport phase, the potential matrix v is the potential matrix within the local potential optimization range when a unit voltage is applied to each transport electrode of the ion trap. k Based on the following formula: In the formula, and When a unit voltage is applied to the transport electrode with serial number i and minimum value imin, the values ​​at z are respectively... min Position and z max The electric potential generated at that location, and When a unit voltage is applied to the transport electrode where the index i is the maximum value imax, the z min Position and z max The electric potential generated at the location.

8. The voltage optimization method for high-fidelity rapid ion transport according to claim 4, characterized in that, When performing rapid transport of multi-ion chains, the value of L is increased.

9. A device for high-fidelity rapid ion transport, comprising an ion trap module, characterized in that, It also includes a host computer module, an FPGA data processing module, a digital-to-analog voltage conversion module, a voltage amplification module, and a low-pass filter module connected in sequence; The host computer module includes an algorithm module and a human-computer interaction interface. The algorithm module is used to optimize the buffer length L of the local potential optimization interval and the macro motion frequency ω in the axial direction. z Calculate the voltage values ​​of each transport electrode in the ion trap during each transport step; the human-machine interface is used to manually set and display the buffer length L of the local potential optimization interval and the macro-motion frequency ω in the axial direction. z It is also used to manually set the voltage of the center electrode, each cap electrode, and each transport electrode of the ion trap module; the host computer module also transmits the voltage control commands of each transport electrode to the FPGA data processing module. The FPGA data processing module is used to receive voltage control commands sent by the host computer module and quickly convert the voltage control commands into commands that can be read by the digital-to-analog voltage conversion module. The digital-to-analog voltage conversion module is used to convert the digital signals sent by the FPGA data processing module into continuous analog voltages and send the analog voltages to the voltage amplification module. The voltage amplification module is used to proportionally amplify the received analog voltage and send the amplified analog voltage to the low-pass filter module. The low-pass filter module is used to filter out noise from the amplified analog voltage to obtain the voltage values ​​of each transport electrode; The ion trap module is used to trap and transport ions and receives the voltage values ​​of each transport electrode.

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