Method, system, computer program and computer readable storage medium for providing control signals for an arbitrary waveform generator

Abstract

A method is provided for providing control signals to an arbitrary waveform generator configured to generate at least two signal sequences applied to at least one quantum particle. The method includes: providing at least two predetermined pulse sequences (1, 2); determining a first block (12), a second block (15), and a third block (16) based on the two predetermined pulse sequences (1, 2); generating a first control signal corresponding to the first block (12), a second control signal corresponding to the second block (15), and a third control signal corresponding to the third block (16); and providing the first control signal, the second control signal, and the third control signal to the arbitrary waveform generator for generating the at least two signal sequences. Furthermore, a system, a computer program, and a computer-readable storage medium are provided.

Description

Technical Field

[0001] This disclosure relates to methods, systems, computer programs, and computer-readable storage media for providing control signals to an arbitrary waveform generator configured to generate at least two signal sequences applied to at least one quantum particle. Background Technology

[0002] Typically, synthesizing a control signal for multiple qubits addressed at a specific resonant frequency requires an oscillator or a device for generating arbitrary waveforms per qubit. In an arbitrary waveform generator, the control signal is stored in the generator's digital memory and played back by the generator's digital-to-analog converter (DAC). The required data rate is enormous, and therefore the memory of an arbitrary waveform generator is always limited. Summary of the Invention

[0003] The aim of this solution is to provide a method for providing control signals to an arbitrary waveform generator with particularly high efficiency. Furthermore, a system, computer program, and computer-readable storage medium for implementing such a method will be provided.

[0004] This objective is achieved through the subject matter of the independent claims. Advantageous embodiments, implementations, and further developments are the subject matter of the corresponding dependent claims.

[0005] A method for providing control signals to an arbitrary waveform generator configured to generate at least two signal sequences applied to at least one quantum particle is described. Exemplarily, the arbitrary waveform generator is configured to receive control signals, for example, from a computer device. Furthermore, the arbitrary waveform is configured to generate signal sequences, for example, based on the control signals, and is configured to provide the signal sequences to the quantum particle to confine, control, and / or manipulate the quantum particle. Specifically, the quantum particle is used to characterize a qubit (or simply quantum bit).

[0006] Exemplarily, quantum particles are formed from ions. Ions can be confined (i.e., trapped), controlled, and / or manipulated by ion traps. Specifically, ion traps are configured to confine at least one ion and / or to modify the electronic state of at least one ion, particularly to perform quantum computing. Ion traps can be Porrod traps, linear ion traps, surface ion traps, and / or multilayer ion traps. Exemplarily, an ion trap includes an assembly of electrodes. For example, a radio frequency (RF) voltage is applied to the electrodes, such that a time-varying electric field is provided, configured to confine and / or modify the ions.

[0007] According to at least one embodiment of the method, at least two predetermined pulse sequences are provided. Specifically, the two predetermined pulse sequences are provided to a computer device. For example, each predetermined pulse sequence includes at least two predetermined pulses. Exemplarily, each predetermined pulse is used to characterize a signal to be provided to a quantum particle, for example, to characterize an RF voltage to be applied to an electrode, including a predetermined frequency, a predetermined amplitude, a predetermined duration, and a predetermined phase.

[0008] For example, each predetermined pulse sequence is used to characterize at least one gate operation on the quantum particle. For instance, the predetermined pulse sequence is configured to be provided to the quantum particle one after another in time (i.e., continuously). Specifically, each predetermined pulse is used to characterize an operation for controlling and / or changing the quantum state of the ion.

[0009] In particular, the pre-set pulses are pre-set for the purpose of performing quantum computing.

[0010] According to at least one embodiment of the method, a first block, a second block, and a third block are determined based on two predetermined pulse sequences. Specifically, the first block is used to characterize a first predetermined pulse having a first predetermined frequency, a first predetermined amplitude, and a first predetermined phase. Specifically, the second block is used to characterize a second predetermined pulse having a second predetermined frequency, a second predetermined amplitude, and a second predetermined phase. Specifically, the third block is used to characterize a third predetermined pulse having a third predetermined frequency, a third predetermined amplitude, and a third predetermined phase.

[0011] According to at least one embodiment of the method, a first block is used to characterize a first predetermined pulse, which exists in both of two predetermined pulse sequences. For example, each of the at least two predetermined pulse sequences includes the first predetermined pulse, such that a first block is determined. Each of the at least two predetermined pulse sequences may include a plurality of predetermined pulses, such that a plurality of blocks are determined accordingly.

[0012] For example, when determining the first block, all predetermined pulses in at least two predetermined pulse sequences are compared. If one of the predetermined pulse sequences includes at least one predetermined pulse that is identical to a predetermined pulse present in the other predetermined pulse sequence, then the first block is determined accordingly, which is specifically used to characterize the first predetermined pulse.

[0013] According to at least one embodiment of the method, a second block is used to characterize a second predetermined pulse that is different from the first predetermined pulse. For example, one of at least two predetermined pulse sequences includes a second predetermined pulse that is different from the first predetermined pulse, such that a second block is determined. Exemplarily, a single second block is determined to characterize the second predetermined pulse.

[0014] For example, when determining the second block, predetermined pulses in at least two predetermined pulse sequences are compared. If one of the predetermined pulse sequences includes at least one predetermined pulse that is different from the first predetermined pulse, then the second block is determined accordingly, which is specifically used to characterize the second predetermined pulse.

[0015] According to at least one embodiment of the method, a third block is used to characterize a third predetermined pulse that is different from the first predetermined pulse and the second predetermined pulse. For example, one of the at least two predetermined pulse sequences includes a third predetermined pulse that is different from both the first and second predetermined pulses, such that a third block is determined. Exemplarily, a single third block is determined to characterize the third predetermined pulse.

[0016] For example, when determining the third block, predetermined pulses in at least two predetermined pulse sequences are compared. If one of the predetermined pulse sequences includes at least one predetermined pulse that is different from the first and second predetermined pulses, then the third block is determined accordingly, which is specifically used to characterize the third predetermined pulse.

[0017] According to at least one embodiment of the method, a first control signal corresponding to a first block, a second control signal corresponding to a second block, and a third control signal corresponding to a third block are generated. Specifically, the first control signal, the second control signal, and the third control signal are different from each other. Furthermore, the first control signal, the second control signal, and the third control signal are configured to be readable and / or processable from an arbitrary waveform generator.

[0018] Specifically, the computer device is configured to sort the blocks according to a predetermined pulse sequence and then generate control signals.

[0019] According to at least one embodiment of the method, a first control signal, a second control signal, and a third control signal are provided to an arbitrary waveform generator to generate at least two signal sequences. For example, the at least two signal sequences are configured to be provided to the quantum particle one after another (i.e., continuously) in time.

[0020] Exemplarily, the arbitrary waveform generator includes an internal processing device configured to receive a first control signal, a second control signal, and a third control signal. Furthermore, the internal processing device is configured to convert the first control signal, the second control signal, and the third control signal into analog voltage signals using a DAC. Subsequently, the arbitrary waveform generator generates at least two signal sequences, for example, based on the analog voltage signals, wherein the at least two signal sequences are continuously sent to the output connector of the arbitrary waveform generator. Exemplarily, the output connector is connected to an ion trap such that at least two signal sequences are continuously provided to the ion trap.

[0021] The methods described above are exemplarily performed in the indicated order. The methods described above are exemplarily computer-implemented methods.

[0022] Typically, a sequence of qubit signals consisting of pulses can be stored linearly in the memory of an arbitrary waveform generator, or it can be segmented. Often, in experiments and / or for computation, the phase of the readout pulse or initial state preparation pulse is altered to sample certain configurations. This is because, typically during experiments and / or computation, most of the pulse signal remains constant.

[0023] The method described herein is conceived in particular by dividing the pulses of at least two predetermined pulse sequences into blocks, wherein the first block is used to characterize pulses that repeat in at least two predetermined pulse sequences, particularly pulses that also repeat in one of the predetermined pulse sequences, and the second and third blocks are used to characterize pulses that are different from the repeating pulses.

[0024] Advantageously, the predetermined pulse sequence is divided into multiple blocks. The first block is used to characterize the same signal set for each experiment, and the second and third blocks are used to characterize the signal that changes during the experiment and / or computation. Therefore, selective replay of these blocks allows for a significant reduction in storage requirements. Advantageously, the generation of the control signal is divided into several transformation steps to reduce computation time and storage.

[0025] According to at least one embodiment of the method, two signal sequences are configured to be provided to a microwave antenna to generate a time-varying electromagnetic field in the region of at least one quantum particle. Specifically, the electrode assembly of the ion trap includes the microwave antenna.

[0026] According to at least one embodiment of the method, each of the at least two predetermined pulse sequences includes a subsequent predetermined pulse. Specifically, each of the at least two predetermined pulse sequences includes one or more subsequent predetermined pulses, wherein the multiple subsequent predetermined pulses are distinct from each other in terms of timestamps. Exemplarily, the number of subsequent predetermined pulses in each of the at least two predetermined pulse sequences is equal to the number of subsequent predetermined pulses.

[0027] According to at least one embodiment of the method, a subsequent block is determined based on two predetermined pulse sequences, wherein the subsequent block is used to characterize a subsequent predetermined pulse that exists in both of the two predetermined pulse sequences.

[0028] According to at least one embodiment of the method, a first block and subsequent blocks are combined into a first block sequence, and a constant sequence signal corresponding to the first block sequence is generated. In particular, if a subsequent predetermined pulse in one of at least two predetermined pulse sequences is directly arranged after the first pulse, then the first block and subsequent blocks are correspondingly (i.e., one after the other) combined into the first block sequence to generate a constant sequence signal.

[0029] According to at least one embodiment of the method, a constant sequence signal, a second control signal, and a third control signal are provided to an arbitrary waveform generator to generate at least two signal sequences.

[0030] Advantageously, pulses corresponding to the second and / or third blocks can be replaced particularly efficiently, thereby reducing computational and storage workload.

[0031] According to at least one embodiment of the method, a pause block is determined based on two predetermined pulse sequences, wherein the pause block is used to characterize the absence of pulses. Exemplarily, there is no signal between a first predetermined pulse and a subsequent pulse (particularly between first predetermined pulses and subsequent pulses that are adjacent to each other), and / or between first predetermined pulses and second predetermined pulses that are directly adjacent within the same predetermined pulse sequence. Specifically, the region between predetermined blocks that are directly adjacent within the same predetermined pulse sequence is used to characterize the pause block.

[0032] According to at least one embodiment of the method, a first block, subsequent blocks, and pause blocks are combined. In particular, the first block, subsequent blocks, and pause blocks are continuously combined into a first pause block sequence, and an additional constant sequence signal corresponding to the first pause block sequence is generated.

[0033] Advantageously, the time when no signal transmission is required is taken into account by including a pause block.

[0034] For example, an additional constant sequence signal, a second control signal, and a third control signal are provided to an arbitrary waveform generator to generate at least two signal sequences.

[0035] According to at least one embodiment of the method, each of two predetermined pulse sequences is divided into a predetermined number of segments, wherein each predetermined pulse comprises at least two segments. Exemplarily, the predetermined pulses in each of the at least two predetermined pulse sequences are arranged sequentially one after another in time. Each of the at least two predetermined pulse sequences extends within a time interval. For example, the segments correspond to a predetermined subset of each time interval, particularly depending on the predetermined number. Exemplarily, the two predetermined pulse sequences are divided into at least 5 or at least 10 segments.

[0036] For example, each first predetermined pulse, second predetermined pulse, third predetermined pulse, and particularly a region with no pulse, comprises multiple segments. Exemplarily, the number of segments in the second predetermined pulse differs from the number of segments in the first predetermined pulse. Similarly, the number of segments in the third predetermined pulse differs from the number of segments in the first predetermined pulse.

[0037] According to at least one embodiment of the method, each of the two predetermined pulse sequences is used to characterize the gate sequence.

[0038] According to at least one embodiment of the method, each of the two predetermined pulse sequences comprises two predetermined pulse subsequences. Exemplarily, each predetermined pulse subsequence is configured to be provided as a signal sequence to a quantum particle.

[0039] According to at least one embodiment of the method, the first block, the second block, and the third block are determined based on at least four predetermined pulse sub-sequences.

[0040] For example, a first block is determined, wherein the first block is used to characterize a first predetermined pulse that exists in at least two of the four predetermined pulse subsequences. In particular, a further first block is determined, wherein the further first block is used to characterize a further first predetermined pulse that exists in at least two of the four predetermined pulse subsequences, and wherein the first predetermined pulse is different from the further first predetermined pulse.

[0041] According to at least one embodiment of the method, a second and / or a third block is dynamically provided to the arbitrary waveform generator during operation of the arbitrary waveform generator.

[0042] According to at least one embodiment of the method, the second block and the third block are different from each other in terms of frequency, amplitude and / or phase.

[0043] Furthermore, a system for providing control signals to an arbitrary waveform generator configured to generate at least two signal sequences applied to at least one quantum particle is described. This system is configured to perform the methods described herein. Therefore, all features and embodiments disclosed in connection with the method are also disclosed in connection with this system, and vice versa.

[0044] According to at least one embodiment, the system includes an arbitrary waveform generator, a computer device configured to generate a first control signal and a second control signal, and an ion trap. Specifically, the computer device is configured to receive inputs such as at least two predetermined pulse sequences. Specifically, the arbitrary waveform generator is connected to the computer device and the ion trap.

[0045] Additionally, a computer program comprising instructions is specified that, when executed by a computer, causes the computer program to perform the methods described herein.

[0046] In addition, a computer-readable storage medium is specified on which the computer program described herein is stored. Attached Figure Description

[0047] The method and ion trap are described in more detail below with reference to exemplary embodiments and associated drawings.

[0048] Figure 1 A predetermined pulse sequence for use in a method according to an exemplary embodiment is shown.

[0049] Figure 2 A flowchart of a method according to an exemplary implementation is shown. Detailed Implementation

[0050] Elements that are identical, similar, or have the same effect are given the same reference numerals in the accompanying drawings. The proportions of the figures and elements shown in the accompanying drawings should not be considered to be true scale. Rather, individual elements may be exaggerated for better representation and / or better understanding.

[0051] Figure 1 Two predetermined pulse sequences, especially Figure 2 The method uses two predetermined pulse sequences, namely a first predetermined pulse sequence 1 and a second predetermined pulse sequence 2, each of which includes two predetermined pulse sub-sequences. For example, the first predetermined pulse sequence 1 includes a first predetermined pulse sub-sequence 3 and a second predetermined pulse sub-sequence 4, and the second predetermined pulse sequence 2 includes a third predetermined pulse sub-sequence 5 and a fourth predetermined pulse sub-sequence 6.

[0052] Each predetermined pulse subsequence of a predetermined pulse sequence is configured to be applied to a corresponding ion. Specifically, the first predetermined pulse subsequence 3 and the third predetermined pulse subsequence 5 are each configured to be applied to a first ion, and the second predetermined pulse subsequence 4 and the fourth predetermined pulse subsequence 6 are each configured to be applied to a second ion. Specifically, the predetermined pulse sequences are configured to be applied to the ions one after another. Specifically, predetermined pulse subsequences of the same predetermined pulse sequence are configured to be applied to the ions simultaneously. The number of predetermined pulse sequences depends on the operation to be performed on the ions. The number of predetermined pulse subsequences depends on the number of ions involved in the operation to be performed.

[0053] The second predetermined pulse subsequence 4 and the fourth predetermined pulse subsequence 6 both include multiple predetermined pulses 7 and 17 that are different from each other, for example, a first predetermined pulse 7 and multiple subsequent predetermined pulses 17, specifically, the first predetermined pulse 7 and the multiple subsequent predetermined pulses 17 are different from each other. Furthermore, the first predetermined pulse subsequence 3 and the third predetermined pulse subsequence 5 both include multiple additional predetermined pulses 8 that are different from each other, for example, additional first predetermined pulses and multiple additional subsequent predetermined pulses, specifically, the additional first predetermined pulses and the multiple additional subsequent predetermined pulses are different from the first predetermined pulse 7 and each of the subsequent predetermined pulses 17. The second predetermined pulse subsequence 4 includes a second predetermined pulse 9 that is different from the first predetermined pulse 7 and each of the subsequent predetermined pulses 17, as well as the additional first predetermined pulse 8 and each of the additional subsequent predetermined pulses. Furthermore, the fourth predetermined pulse subsequence 6 includes a third predetermined pulse 10, which is different from the first predetermined pulse 7, another first predetermined pulse 8, each of the subsequent predetermined pulses 17, and each of the other subsequent predetermined pulses and the second predetermined pulse 9. The pulses are temporally spaced apart by interval time intervals, during which there are no pulses 11.

[0054] Each predetermined pulse sequence extends along time t within a time interval. The time interval of the predetermined pulse sequence is specifically divided into consecutive segments s of equal length.

[0055] according to Figure 2 Method phase S1 of an exemplary implementation includes providing in Figure 1 The example shows at least two predetermined pulse sequences.

[0056] Subsequently, in method phase S2, a first block 12, a subsequent block 18, and, exemplary, another first block 13 and another subsequent block 20 and / or pause block, a second block 15, and a third block 16 are determined based on two predetermined pulse sequences. The first block 12 is used to characterize, for example, in... Figure 1 The first predetermined pulse 7, marked in the middle, exists in both of the two predetermined pulse sequences, particularly in at least two predetermined pulse subsequences within the predetermined pulse subsequences. Exemplarily, the additional first block 13 is used to characterize, for example, in... Figure 1 The additional first predetermined pulse 8, marked in the middle, exists in both of the two predetermined pulse sequences, particularly in at least two predetermined pulse subsequences within the predetermined pulse subsequences. Exemplarily, the pause block is used to characterize, for example, in... Figure 1The pulse-free 11 is marked in the middle.

[0057] The second block 15 is used to characterize the second predetermined pulse 9, which is related to, for example, in... Figure 1 The first predetermined pulse 7 marked in the middle is different, and the third block 16 is used to characterize the third predetermined pulse 10, which is different from, for example, in... Figure 1 The first predetermined pulse 7 and the second predetermined pulse 9 marked in the middle are different.

[0058] In method phase S3, a first control signal corresponding to the first block 12, and an additional first control signal, exemplarily corresponding to another first block 13, and / or a pause control signal corresponding to a pause block, a second control signal corresponding to the second block 15, and a third control signal corresponding to the third block 16 are generated.

[0059] For example, a first predetermined pulse corresponding to the first block 12 and another first predetermined pulse of the other first block 13 are combined accordingly. Specifically, a sum of the first block 12 and the other first block 13 is generated. Specifically, a summation control signal corresponding to the first block 12 and the other first block 13 is generated. Similarly, a subsequent predetermined pulse 17 corresponding to the subsequent block 18 and another subsequent predetermined pulse 19 corresponding to the other subsequent block 20 are combined accordingly. This results in a sum of the subsequent block 18 and the other subsequent block 20, both corresponding to the same segment. Specifically, another summation control signal corresponding to the corresponding subsequent block 18 and the corresponding other subsequent block 20 is generated.

[0060] Specifically, based on the corresponding pulse and no-pulse sequential arrangement of the first block 12, the subsequent block 18, and the pause block 14, the second predetermined pulse subsequence 4 and the fourth predetermined pulse subsequence 6 are combined into the first pause block sequence. Subsequently, another constant sequence signal corresponding to the first pause block sequence is generated.

[0061] Furthermore, specifically, based on the corresponding pulse and no-pulse continuous arrangement of another first block 13, another subsequent block 20, and a pause block 14, the first predetermined pulse subsequence 3 and the third predetermined pulse subsequence 5 are combined into another first pause block sequence. Subsequently, additional constant sequence signals corresponding to the first pause block sequence are generated.

[0062] Subsequently, in method step S4, a first control signal, and exemplary additional first control signals and / or pause control signals (particularly additional constant sequence signals and / or additional additional constant sequences), a second control signal, and a third control signal are provided to an arbitrary waveform generator for generating at least two signal sequences. Specifically, a summation control signal is provided to the arbitrary waveform generator for generating at least two signal sequences.

[0063] This invention is not limited to the exemplary embodiments described herein. Rather, the invention covers any new features and any combination of features, particularly any combination of features in the claims, even if the feature or combination itself is not expressly indicated in the claims or exemplary embodiments.

[0064] Figure Labels

[0065] 1. First predetermined pulse sequence

[0066] 2. Second predetermined pulse sequence

[0067] 3. First predetermined pulse subsequence

[0068] 4. Second predetermined pulse subsequence

[0069] 5. Third predetermined pulse subsequence

[0070] 6. Fourth predetermined pulse subsequence

[0071] 7 First Predetermined Pulse

[0072] 8. Another first predetermined pulse

[0073] 9 Second Predetermined Pulse

[0074] 10 Third Predetermined Pulse

[0075] 11 No Pulse

[0076] 12 First piece

[0077] 13 The other first piece

[0078] 14 pause blocks

[0079] 15 Second piece

[0080] 16 Third piece

[0081] 17 Subsequent Pre-ordered Pulses

[0082] 18 subsequent blocks

[0083] 19 additional subsequent scheduled pulses

[0084] 20 additional subsequent blocks

[0085] t time

[0086] S segment

[0087] S1…S6 Method Phase

Claims

1. A method for providing control signals to an arbitrary waveform generator, the arbitrary waveform generator being configured to generate at least two signal sequences applied to at least one quantum particle, the method comprising: - Provide at least two predetermined pulse sequences (1, 2). - Based on the two predetermined pulse sequences (1, 2), the first block (12), the second block (15), and the third block (16) are determined, wherein, - The first block (12) is used to characterize a first predetermined pulse (7), which exists in both of the two predetermined pulse sequences (1, 2). - The second block (15) is used to characterize a second predetermined pulse (9), which is different from the first predetermined pulse (7), and - The third block (16) is used to characterize a third predetermined pulse (10), which is different from the first predetermined pulse (7) and the second predetermined pulse (9). - Generate a first control signal corresponding to the first block (12), a second control signal corresponding to the second block (15), and a third control signal corresponding to the third block (16), and - The first control signal, the second control signal, and the third control signal are provided to the arbitrary waveform generator to generate the at least two signal sequences.

2. The method according to claim 1, wherein, - The two signal sequences are configured to be provided to the microwave antenna to generate a time-varying electromagnetic field in the region of the at least one quantum particle.

3. The method according to claim 1 or 2, wherein, - Each of the at least two predetermined pulse sequences (1, 2) includes a subsequent predetermined pulse (17). - A subsequent block (18) is determined based on the two predetermined pulse sequences (1, 2), wherein the subsequent block (18) is used to characterize the subsequent predetermined pulse (17), which exists in either of the two predetermined pulse sequences (1, 2). - The first block (12) and the subsequent block (18) are combined into a first block sequence, and a constant sequence signal corresponding to the first block sequence is generated. - The constant sequence signal, the second control signal, and the third control signal are provided to the arbitrary waveform generator to generate the at least two signal sequences.

4. The method according to claim 3, wherein, - Determine the pause block based on the two predetermined pulse sequences (1, 2). - The pause block is used to characterize the absence of pulses (11), and - Combine the first block (12), the subsequent block (18), and the pause block.

5. The method according to any one of claims 1 to 4, wherein, Before determining the block, - Divide each of the two predetermined pulse sequences (1, 2) into a predetermined number of segments, and - Each predetermined pulse in the predetermined pulse consists of at least two segments.

6. The method according to any one of claims 1 to 5, wherein, - Each of the two predetermined pulse sequences (1, 2) is used to characterize the gate sequence.

7. The method according to any one of claims 1 to 6, wherein, - Each of the two predetermined pulse sequences (1, 2) includes two predetermined pulse subsequences (3, 4, 5, 6), and - The first block (12), the second block (15), and the third block (16) are determined based on at least four predetermined pulse subsequences (3, 4, 5, 6).

8. The method according to any one of claims 1 to 7, wherein, - During the operation of the arbitrary waveform generator, the second block (15) and / or the third block (16) are dynamically provided to the arbitrary waveform generator.

9. The method according to any one of claims 1 or 8, wherein, - The second block (15) and the third block (16) are different from each other in terms of frequency, amplitude and / or phase.

10. A system for providing control signals to an arbitrary waveform generator configured to generate at least two signal sequences applied to at least one quantum particle, the at least two signal sequences being used to characterize at least two predetermined pulse sequences (1, 2), the system being configured to perform the method according to any one of the preceding claims.

11. The system of claim 10, comprising: - Arbitrary waveform generator - A computer device configured to generate a first control signal and a second control signal, and - Ion trap.

12. A computer program comprising instructions that, when executed by a computer, cause the computer program to perform the method according to any one of claims 1 to 9.

13. A computer-readable storage medium on which the computer program according to claim 12 is stored.

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