CONTROL SYSTEM AND QUANTUM COMPUTER SYSTEM

Abstract

A control system (1) for controlling a microwave output system (2) for emitting electromagnetic radiation to at least two registers (3), each comprising at least one ion for quantum computing, comprising: an integrated circuit (5), a local oscillator (6), at least two digital-to-analog converter systems (7), each connected to the integrated circuit (5), and at least two frequency mixers (8), each connected to the local oscillator (6), wherein each of the at least two digital-to-analog converter systems (7) is connected to one of the at least two frequency mixers (8), and each of the at least two frequency mixers (8) is connected to at least one part of the microwave output system (2) that is assigned to one of the at least two registers (3). A quantum computer system (15) is also provided.

Description

[0001] The present disclosure relates to a control system for controlling a microwave output system for emitting electromagnetic radiation to at least two registers, each of which includes at least one ion for quantum computing, and a quantum computer system.

[0002] In microwave-controlled trapped ion qubits, each qubit is typically manipulated with microwave pulses characterized by frequency, phase, pulse duration, and amplitude. A different number of qubits must be managed per register, each requiring specific pulse parameters for precise control. Depending on the position of a qubit, an individually adapted amplitude, frequency, and phase are necessary.

[0003] The task is to provide a control system suitable for efficiently controlling the microwave output system. Additionally, a quantum computing system is to be provided.

[0004] These objectives are achieved through the subject matter of the independent claims. Advantageous embodiments, implementations, and further developments are the subject matter of the respective dependent claims.

[0005] The control system for controlling a microwave output system for emitting electromagnetic radiation to at least two registers, each containing at least one ion for quantum computing, is described. The microwave output system is configured, for example, to emit electromagnetic radiation to at least two registers, each containing at least one ion for quantum computing. For example, the microwave output system is configured to supply electromagnetic radiation to an ion trap with the at least two registers, each register comprising a processing area. The processing area is configured, in particular, to accommodate at least one ion, for example, a plurality of ions. For example, at most 100 ions or at most 60 ions are provided in the processing area.For example, the microwave output system is configured to provide electromagnetic radiation to the ions in the respective processing area.

[0006] The microwave output system can comprise at least two microwave antennas, each assigned to a register, or the microwave output system can comprise a plurality of electrically conductive elements, with at least some of the electrically conductive elements being assigned to a register. In particular, the emitted electromagnetic radiation of the microwave output system includes a near-field region in which the respective ion is intended to be located. For example, the beams emitted by adjacent electrically conductive elements interact with each other and form the emitted electromagnetic radiation of the microwave output system with the near-field region and a far-field region. The distance between the electrically conductive elements and the processing area is, for example, at most 1.5 times or 1 times the wavelength of the emitted electromagnetic radiation from the electrically conductive elements.

[0007] The ion trap can be a Paul trap, a linear ion trap, a surface ion trap, or a multilayer ion trap. The ion trap comprises, for example, a set of electrodes configured to trap and / or manipulate at least one ion within a processing area. For instance, a high-frequency voltage is applied to at least some of the electrodes in the set, generating a time-varying electric field within the processing area that is configured to trap and / or manipulate the ion. For example, the ion intersects a trapping axis and / or oscillates around a trapping axis within the processing area.

[0008] For example, electromagnetic radiation, in particular microwave radiation, is applied to at least some trapped ions, especially by the microwave output system. The electromagnetic radiation is configured, for example, to induce a transition between the energy levels of at least some of the trapped ions. For example, the application of the electromagnetic radiation performs an operation on the quantum states of the trapped ions, such as qubit rotations or state preparations. Microwave radiation is particularly characteristic of electromagnetic radiation with a frequency of at least 0.1 GHz and at most 500 GHz, and especially at least 0.3 GHz and at most 300 GHz.

[0009] The ion trap comprises, for example, at least one magnetic arrangement configured to generate a magnetic field in the processing area. This magnetic arrangement may include at least one permanent magnet arrangement and / or at least one coil. The magnetic arrangement is, for example, spaced laterally and / or vertically from the processing area. In particular, the magnetic arrangement is configured to generate a gradient of magnetic field strength in the processing area, e.g., along the capture axis. That is, the magnetic field of the magnetic arrangement has different strengths for different positions in the processing area and, in particular, for different positions along the capture axis.Advantageously, when there are a large number of ions in the processing area, the resonance frequency of each of the ions on which the size gradient of the magnetic field of the magnet arrangement acts is individual for each ion in the processing area.

[0010] According to at least one embodiment, the control system comprises an integrated circuit. The integrated circuit is, for example, a field-programmable gate array (FPGA) and / or an application-specific integrated circuit (ASIC).

[0011] For example, the microwave intensity used to flip an ion can differ depending on whether the ion is located in a central region or at the edge of the register. The integrated circuit is configured, for instance, to make individual corrections to a waveform depending on the application and specific ions, such as particular ion positions within the respective register.

[0012] According to at least one embodiment, the control system includes a local oscillator. The local oscillator is an electronic circuit configured to generate a stable and / or precise frequency signal as its output. For example, the integrated circuit is configured to individually tune the output of the local oscillator for each register.

[0013] According to at least one embodiment, the control system comprises at least two digital-to-analog converter systems, each connected to the integrated circuit. For example, each digital-to-analog converter system comprises at least one digital-to-analog converter. For example, each digital-to-analog converter is configured to convert digital input signals from the integrated circuit, corresponding, for example, to discrete numerical values, into analog output signals, such as a continuous voltage or a continuous current.

[0014] According to at least one embodiment, the control system comprises at least two frequency mixers, each connected to the local oscillator. Each frequency mixer is configured, for example, to combine two input signals and generate a new signal that includes the sum and difference of the frequencies of the input signals.

[0015] According to at least one embodiment of the control system, each of the at least two digital-to-analog converter systems is connected to one of the at least two frequency mixers. The frequency mixer is configured, for example, to combine the input signals of the local oscillator and the respective digital-to-analog converter system for that frequency mixer. The input signals for each frequency mixer include, for example, an output signal of the local oscillator and the respective analog output signal of the digital-to-analog converter system.

[0016] According to at least one embodiment of the control system, each of the at least two frequency mixers is connected to at least one part of the microwave output system that is assigned to one of the at least two registers. For example, the number of digital-to-analog converter systems and the number of frequency mixers is equal to the number of registers. For example, exactly one digital-to-analog converter system and exactly one frequency mixer is assigned to exactly one register.

[0017] One idea is to use the described control system with its units, where different pulse parameters can be provided for the precise control of each ion in its respective register. Advantageously, such a control system can handle the real-time control of the local oscillators and the digital-to-analog converters in the digital-to-analog converter systems, enabling dynamic adaptation of the microwave pulses to the specific needs of each ion.

[0018] Since real-time control of the microwave signal generators is crucial for maintaining the precision and accuracy required for effective quantum computing, the described control system advantageously increases the flexibility and scalability of quantum computer systems.

[0019] The integrated circuit advantageously controls, for example, the local oscillator and the digital-to-analog converter systems by defining the pulse parameters for each register. Advantageously, such a control system allows independent control of ions in different registers by using a single local oscillator and independent digital-to-analog converter systems, each capable of manipulating a number of ions per register.

[0020] According to at least one embodiment, the control system comprises at least two signal power combiners. For example, the signal power combiners are connected downstream of the respective digital-to-analog converter system.

[0021] According to at least one embodiment of the control system, each of the at least two digital-to-analog converter systems is connected to one of the at least two signal power combiners. If the digital-to-analog converter systems each comprise more than one digital-to-analog converter, the digital-to-analog converters of a digital-to-analog converter system are connected to one signal power combiner.

[0022] For example, each signal power combiner is configured to combine the analog output signals of the digital-to-analog converter system into a combined power output signal. The input signals for each frequency mixer include, for example, the output signal of the local oscillator and the respective combined power output signal of the signal power combiner.

[0023] According to at least one embodiment of the control system, each of the at least two signal power combiners is connected to one of the at least two frequency mixers. For example, exactly one signal power combiner is arranged between the respective digital-to-analog converter systems and the respective frequency mixer.

[0024] According to at least one embodiment, the control system comprises at least two power amplifiers.

[0025] According to at least one embodiment of the control system, each of the at least two frequency mixers is connected to one of the at least two power amplifiers. For example, the power amplifiers are connected downstream of the respective frequency mixers. The power amplifiers are each formed, for example, with an up-converter. For example, the power amplifiers are connected to the microwave output system. In particular, the microwave output system is arranged between the respective frequency mixer and a part of the microwave output system corresponding to a respective register.

[0026] According to at least one embodiment of the control system, each of the at least two power amplifiers is connected to at least one part of the microwave output system that is assigned to one of the at least two registers.

[0027] According to at least one embodiment, the control system includes a master clock. The master clock is configured as a reference, in particular for the local oscillator and the digital-to-analog converter systems.

[0028] According to at least one embodiment of the control system, the main clock generator is connected to the local oscillator, and the main clock generator is connected to all digital-to-analog converter systems.

[0029] According to at least one embodiment, the control system comprises a waveform memory connected to the integrated circuit. For example, the waveform memory is configured to store phase increment values ​​used to generate precise waveforms, as well as digital representations of desired pulses, which are used, in particular, to generate the desired signal.

[0030] For example, the waveform memory contains a large number of standard pulse shapes configured to serve as input for the integrated circuit. The number of standard pulse shapes is typically at least 100 Mega instructions and / or at most 1000 Mega instructions, particularly in the case of a direct digital synthesis (DDS) integrated circuit. The information from the standard pulse shapes in the waveform memory is configured for real-time processing, with individual, ultrafast corrections being applied by the integrated circuit.

[0031] In particular, the integrated circuit is configured to provide one output per register based on the multitude of standard pulse shapes.

[0032] According to at least one embodiment, the control system includes a sequence library connected to the waveform memory. For example, the sequence library is configured to manage sequences of waveforms. This has the advantage that complex, multi-level signal patterns can be created by defining a series of waveform events. Furthermore, it enables seamless transitions between different waveforms and precise timing control, which is particularly advantageous for the demanding signal generation required for implementing complex quantum circuits.

[0033] For example, the sequence library includes calibration data for at least some of the several standard pulse shapes. Integrating the sequence library with calibration data advantageously ensures precise control.

[0034] According to at least one embodiment of the control system, each of the at least two digital-to-analog converter systems comprises at least one digital-to-analog converter.

[0035] According to at least one embodiment of the control system, the at least one digital-to-analog converter is configured to generate at least one tone.

[0036] According to at least one embodiment of the control system, the number of digital-to-analog converters in the corresponding digital-to-analog converter system depends on the number of ions of the corresponding register and the number of tones that the corresponding digital-to-analog converters can generate.

[0037] According to at least one embodiment of the control system, the number of tones of the corresponding digital-to-analog converter system is equal to the number of ions of the corresponding register. Advantageously, each digital-to-analog converter system is thus able to manipulate a number of ions per register.

[0038] According to at least one embodiment of the control system, all digital-to-analog converters are interconnected on the input side via a main clock bus.

[0039] According to at least one embodiment of the control system, all digital-to-analog converters of an analog converter system are interconnected on the output side via a signal power combiner bus.

[0040] According to at least one embodiment of the control system, the integrated circuit is additionally connected to the local oscillator.

[0041] Furthermore, a quantum computer system is specified, which includes the control system described above. This means that the features relating to the control system are also applicable to the quantum computer system and vice versa.

[0042] According to at least one embodiment, the quantum computer system comprises a microwave output system as described herein.

[0043] According to at least one embodiment, the quantum computer system comprises an ion trap with at least two registers as described above.

[0044] The control system and the quantum computer system are explained in more detail below with reference to exemplary embodiments and the associated figures. Fig. Figure 1 shows a schematic view of the control system according to an exemplary embodiment. Fig. Figure 2 shows a schematic representation of the quantum computer system according to an exemplary embodiment.

[0045] Identical, similar, or similarly appearing elements in the figures are marked with the same reference symbols. The figures and the proportions of the elements depicted within them are not to be considered as being to scale. Rather, individual elements may be depicted as disproportionately large for better representation and / or clarity.

[0046] The control system 1 according to the embodiment of the Fig. The control system 1 comprises an integrated circuit 5 connected to a waveform memory 12. A sequence library 13 is also connected to the waveform memory 12. The control system 1 further comprises a local oscillator 6 and a plurality of digital-to-analog converter systems 7. The local oscillator 6 and each digital-to-analog converter system 7 are connected to the integrated circuit 5. A master clock 11 is connected to the local oscillator 6 and to each digital-to-analog converter system 7.

[0047] Each of the digital-to-analog converter systems 7 comprises a plurality of digital-to-analog converters 14. All digital-to-analog converters 14 are interconnected at one input side facing the integrated circuit 5 by an integrated circuit bus connected to the integrated circuit 5. In addition, all digital-to-analog converters 14 are interconnected at the input side via a master clock bus.

[0048] Each analog-to-analog converter system is further connected to a signal power combiner 9. In particular, all digital-to-analog converters 14 of an analog-to-analog converter system are interconnected on the output side via a signal power combiner bus of the respective signal power combiner 9.

[0049] Each of the signal power combiners 9 is connected to a frequency mixer 8. Furthermore, each frequency mixer 8 is connected to the local oscillator 6. Each frequency mixer 8 is also connected to a power amplifier 10. The power amplifiers 10 are connected to at least one part of a microwave output system 2 of an ion trap 4, with each part being assigned to a register 3 of the ion trap 4.

[0050] Such a control system 1 can advantageously be implemented relatively close to the ion trap 4.

[0051] The quantum computer system according to the embodiment of the Fig.2 comprises the control system 1, the microwave output system 2, and a quantum processor with the ion trap 4, arranged in a chamber that provides a vacuum and / or cryogenic environment. The quantum processor and a possible laser system are connected via links to a control electronics system, which is connected to a device that is a classical computer device.

[0052] The invention is not limited to the exemplary embodiments by its description. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the claims, even if this feature or combination itself is not expressly specified in the claims or the exemplary embodiments. Reference sign 1 Control system 2 microwave dispensing systems 3 Register 4 ion trap 5 integrated circuit 6 Local oscillator 7 Digital-to-Analog Converter System 8 frequency mixers 9 signal power combiners 10 power amplifiers 11 Main clock generator 12 waveform memories 13 Sequence Library 14 digital-to-analog converters 15 quantum computer systems 16th Chamber 17 connections 18 Control electronics system 19 Device

Claims

Control system (1) for controlling a microwave output system (2) for emitting electromagnetic radiation to at least two registers (3), each comprising at least one ion for quantum computing, comprising: - an integrated circuit (5), - a local oscillator (6), - at least two digital-to-analog converter systems (7), each connected to the integrated circuit (5), - at least two frequency mixers (8), each connected to the local oscillator (6), wherein - each of the at least two digital-to-analog converter systems (7) is connected to one of the at least two frequency mixers (8), and - each of the at least two frequency mixers (8) is connected to at least one part of the microwave output system (2) that is assigned to one of the at least two registers (3). Control system (1) according to claim 1, further comprising: - at least two signal power combiners (9), wherein: - each of the at least two digital-to-analog converter systems (7) is connected to one of the at least two signal power combiners (9), and - each of the at least two signal power combiners (9) is connected to one of the at least two frequency mixers (8). Control system (1) according to one of claims 1 or 2, further comprising: - at least two power amplifiers (10), wherein: - each of the at least two frequency mixers (8) is connected to one of the at least two power amplifiers (10), and - each of the at least two power amplifiers (10) is connected to at least one part of the microwave output system (2) that is assigned to one of the at least two registers (3). Control system (1) according to one of claims 1 to 3, further comprising: - a master clock generator (11), wherein: - the master clock generator (11) is connected to the local oscillator (6), and - the master clock generator (11) is connected to all digital-to-analog converter systems (7). Control system (1) according to one of claims 1 to 4, further comprising - a waveform memory (12) connected to the integrated circuit (5), and - a sequence library (13) connected to the waveform memory (12). Control system (1) according to one of claims 1 to 5, wherein each of the at least two digital-to-analog converter systems (7) comprises at least one digital-to-analog converter (14), and the at least one digital-to-analog converter (14) is configured to generate at least one tone. Control system (1) according to claim 6, wherein a number of digital-to-analog converters (14) in the corresponding digital-to-analog converter system (7) depends on a number of ions of the corresponding register (3) and the number of tones that the corresponding digital-to-analog converters (14) can generate, and the number of tones of the corresponding digital-to-analog converter system (7) is equal to the number of ions of the corresponding register (3). Control system (1) according to claim 6 or 7, wherein all digital-to-analog converters (14) are interconnected on the input side via a master clock bus, and / or all digital-to-analog converters (14) of an analog converter system are interconnected on the output side via a signal power combiner bus. Control system (1) according to one of claims 1 to 8, wherein the integrated circuit (5) is additionally connected to the local oscillator (6). Quantum computer system (15), comprising: - the control system (1) according to any one of claims 1 to 9, - a microwave output system (2), and - an ion trap (4) with the at least two registers (3).

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