Signal generation device and method for quantum chip measurement and control system

Abstract

The present invention provides a signal generation device and method for a quantum chip measurement and control system, primarily relating to the field of quantum computing technology. The signal generation device comprises: an optical frequency comb light source for generating a frequency comb optical signal comprising multiple initial spectral lines with equal frequency spacing; a spectrum beam splitter for spatially separating the multiple initial spectral lines included in the frequency comb optical signal to obtain discrete spectral lines for each of the multiple initial spectral lines; a modulator array for amplitude and phase modulating each discrete spectral line to obtain modulated spectral lines for each of the multiple discrete spectral lines; a spectrum combiner for combining the multiple modulated spectral lines to obtain a composite optical signal; a dispersion processing module for performing dispersion processing on the composite optical signal to generate a time-domain optical signal through frequency-time mapping; and a photodetector for converting the time-domain optical signal into a radio frequency electrical signal to obtain a target radio frequency signal.

Description

Technical Field

[0001] The present invention relates to the field of quantum computing technology, and more specifically, to a signal generating device and method. Background Art

[0002] In the field of quantum computing, operations such as initializing, manipulating, reading, and correcting errors on quantum chips require the generation of a variety of desired complex RF waveforms, such as high-frequency pulses and broadband modulated signals. Therefore, arbitrary waveform generators (AWGs), as signal generation devices, are often indispensable in quantum measurement and control systems.

[0003] However, the signal frequency generated by traditional RF arbitrary waveform generators is usually in the range of 10GHz (~10GHz) and has limited bandwidth. As a result, the generated waveform is not accurate and ideal, which in turn reduces the fidelity of operation. Summary of the Invention

[0004] In view of this, the present invention provides a signal generation device and method for a quantum chip measurement and control system.

[0005] One aspect of the present invention provides a signal generating device for a quantum chip measurement and control system, the signal generating device comprising: an optical frequency comb light source for generating a frequency comb optical signal comprising a plurality of initial spectral lines with equal frequency intervals; a spectrum beam splitter for spatially separating the plurality of initial spectral lines comprised in the frequency comb optical signal to obtain discrete spectral lines of the plurality of initial spectral lines; a modulator array for amplitude and phase modulating each of the discrete spectral lines to obtain modulated spectral lines of the plurality of discrete spectral lines; a spectrum combiner for combining the plurality of modulated spectral lines to obtain a composite optical signal; a dispersion processing module for performing dispersion processing on the composite optical signal to generate a time-domain optical signal through frequency-time mapping; and a photodetector for converting the time-domain optical signal into a radio frequency electrical signal to obtain a target radio frequency signal.

[0006] According to an embodiment of the present invention, the above-mentioned signal generating device also includes an optical beam splitter and a plurality of the above-mentioned photodetectors, and the above-mentioned optical beam splitter and the plurality of the above-mentioned photodetectors are arranged inside the dilution refrigerator; the above-mentioned time-domain optical signal is transmitted to the above-mentioned optical beam splitter through an optical fiber; the above-mentioned optical beam splitter is used to split the above-mentioned time-domain optical signal into multiple time-domain optical signals, wherein the waveform of each time-domain optical signal is consistent with the waveform of the above-mentioned time-domain optical signal generated by the above-mentioned dispersion processing module; the plurality of the above-mentioned photodetectors are used to convert the multiple time-domain optical signals into multiple radio frequency electrical signals to generate multiple radio frequency arbitrary waveforms.

[0007] According to an embodiment of the present invention, the above-mentioned signal generating device also includes an optical amplifier, which is used to amplify the above-mentioned time domain optical signal to obtain an amplified time domain optical signal; the above-mentioned optical splitter is also used to split the above-mentioned amplified time domain optical signal into the above-mentioned multi-path time domain optical signals.

[0008] According to an embodiment of the present invention, the modulator array comprises a spatial light modulator array, and the spatial light modulator array is used to independently perform amplitude and phase modulation on each of the discrete spectral lines.

[0009] According to an embodiment of the present invention, the above-mentioned modulator array includes an amplitude modulator array and a phase modulator array; the above-mentioned amplitude modulator array is used to independently perform amplitude modulation on each of the discrete spectral lines; the above-mentioned phase modulator array is configured to be cascaded with the above-mentioned amplitude modulator array, and the above-mentioned phase modulator array is used to independently perform phase modulation on each of the discrete spectral lines.

[0010] According to an embodiment of the present invention, the spectrum splitter, the modulator array, and the spectrum combiner are integrated into a chip-type control array.

[0011] According to an embodiment of the present invention, the above-mentioned spectrum splitter includes an input waveguide array grating, which is used to spatially separate the multiple initial spectral lines included in the above-mentioned frequency comb optical signal to obtain discrete spectral lines of the multiple initial spectral lines; the above-mentioned modulator array includes an amplitude modulator array and a phase modulator array, and the above-mentioned amplitude modulator array and the above-mentioned phase modulator array are integrated on the above-mentioned chip-type control array to independently perform amplitude and phase modulation on each of the above-mentioned discrete spectral lines; the above-mentioned spectrum combiner includes an output waveguide array grating, which combines the above-mentioned multiple modulated spectral lines to obtain the above-mentioned synthetic optical signal.

[0012] According to an embodiment of the present invention, the optical frequency comb light source includes an optical frequency comb module and an optical switch; wherein the optical frequency comb module is used to generate a plurality of the frequency comb optical signals with different central wavelengths, and the optical switch is used to select different frequency comb optical signals.

[0013] Another aspect of the present invention provides a signal generation method for a quantum chip measurement and control system, which is applied to the above-mentioned signal generation device. The above-mentioned signal generation method includes: spatially separating multiple initial spectral lines with equal frequency intervals included in a frequency comb optical signal to obtain discrete spectral lines of each of the multiple initial spectral lines; performing amplitude and phase modulation on each of the above-mentioned discrete spectral lines to obtain modulated spectral lines of each of the multiple above-mentioned discrete spectral lines; combining the multiple above-mentioned modulated spectral lines to obtain a composite optical signal; performing dispersion processing on the above-mentioned composite optical signal to generate a time domain optical signal through frequency-time mapping; and converting the above-mentioned time domain optical signal into a radio frequency electrical signal to obtain a target radio frequency signal.

[0014] According to an embodiment of the present invention, the method further includes: amplifying the time-domain optical signal to obtain an amplified time-domain optical signal; introducing the amplified time-domain optical signal into a dilution refrigerator via an optical fiber to split the amplified time-domain optical signal into multiple time-domain optical signals; and converting the multiple time-domain optical signals into multiple radio frequency signals to generate multiple radio frequency arbitrary waveforms.

[0015] According to an embodiment of the present invention, an optical frequency comb light source is used to generate multiple spectral lines with equal frequency intervals, and the amplitude and phase of each spectral line are independently controlled by a modulator array to implement Fourier domain spectrum editing to generate high-frequency, large-bandwidth RF arbitrary waveforms, thereby meeting the requirements of quantum bit manipulation for high-frequency, high-precision microwave signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0017] Figure 1 A schematic diagram of a signal generating device for a quantum chip measurement and control system according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of a signal generating device according to a specific embodiment of the present invention is shown.

[0019] Figure 3 FIG. 1 is a schematic diagram showing a signal generating device according to another specific embodiment of the present invention.

[0020] Figure 4 A schematic diagram of a signal generating device including a spatial light modulator array according to a specific embodiment of the present invention is shown.

[0021] Figure 5 A schematic diagram of a signal generating device including an amplitude modulator array and a phase modulator array according to a specific embodiment of the present invention is shown.

[0022] Figure 6A schematic diagram of a chip-integrated control array according to a specific embodiment of the present invention is shown.

[0023] Figure 7 A schematic diagram of a signal generating device including a specific chip-integrated control array structure according to a specific embodiment of the present invention is shown.

[0024] Figure 8 A schematic diagram of a signal generating device including an optical frequency comb module and an optical switch according to a specific embodiment of the present invention is shown.

[0025] Figure 9 A flow chart of a signal generation method for a quantum chip measurement and control system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0027] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0028] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0029] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0030] In the field of quantum computing, operations such as initializing, manipulating, reading, and correcting errors on quantum chips require the generation of a variety of desired complex RF waveforms, such as high-frequency pulses and broadband modulated signals. Therefore, arbitrary waveform generators (AWGs), as signal generation devices, are often indispensable in quantum measurement and control systems.

[0031] However, the signal frequency generated by traditional RF arbitrary waveform generators is usually in the 10GHz range (~10GHz) and has limited bandwidth. As a result, the generated waveform is not accurate and ideal, which in turn reduces the fidelity of the system.

[0032] At the same time, the RF coaxial cable used with arbitrary waveform generators has a certain size. When the number of qubits increases significantly, the volume occupied by the cable will increase significantly, limiting the expansion of the bit number. Furthermore, the loss caused by the cable when transmitting high-frequency signals will cause the temperature of the refrigerator system to rise, reducing the system's ability to provide a low-temperature operating environment. Furthermore, because a single cable only transmits one signal, crosstalk between the various signals becomes a significant issue when the number of bits is large.

[0033] In view of this, an embodiment of the present invention utilizes an optical frequency comb light source to generate multiple spectral lines with equal frequency intervals, and independently regulates the amplitude and phase of each spectral line through a modulator array to implement Fourier domain spectrum editing, so as to generate high-frequency, large-bandwidth RF arbitrary waveforms, thereby meeting the requirements of quantum bit manipulation for high-frequency, high-precision microwave signals.

[0034] Specifically, an embodiment of the present invention provides a signal generating device for a quantum chip measurement and control system, comprising: an optical frequency comb light source, for generating a frequency comb optical signal comprising a plurality of initial spectral lines with equal frequency intervals; a spectrum beam splitter, for spatially separating the plurality of initial spectral lines included in the frequency comb optical signal to obtain discrete spectral lines of the plurality of initial spectral lines; a modulator array, for performing amplitude and phase modulation on each discrete spectral line to obtain modulated spectral lines of the plurality of discrete spectral lines; a spectrum combiner, for combining the plurality of modulated spectral lines to obtain a synthesized optical signal; a dispersion processing module, for performing dispersion processing on the synthesized optical signal to generate a time domain optical signal through frequency-time mapping; and a photodetector, for converting the time domain optical signal into a radio frequency electrical signal to obtain a target radio frequency signal.

[0035] Figure 1 A schematic diagram of a signal generating device for a quantum chip measurement and control system according to an embodiment of the present invention is shown.

[0036] like Figure 1 As shown, the signal generating device includes an optical frequency comb light source 1, a spectrum beam splitter 2, a modulator array 3, a spectrum combiner 4, a dispersion processing module 5, and a photodetector array 6.

[0037] like Figure 1 As shown, the output end of the optical frequency comb light source 1 is connected to the input end of the spectrum splitter 2 to transmit the generated frequency comb optical signal to the spectrum splitter 2.

[0038] In this embodiment, an optical frequency comb light source 1 is used to generate a frequency comb optical signal, providing fundamental frequency components for subsequent complex waveform generation. The spectrum of the frequency comb optical signal includes multiple initial spectral lines with equally spaced frequencies, each corresponding to a precise frequency.

[0039] In a specific embodiment, the frequency can be expressed as , where f0 represents the starting frequency, that is, the frequency value of the first spectral line in the frequency comb; Indicates the frequency interval, that is, the frequency difference between two adjacent spectral lines. The relationship between it and the pulse repetition interval T is ;in, , N represents the number of spectral lines.

[0040] In one specific embodiment, the optical frequency comb light source 1 can be implemented using a mode-locked laser, a pumped microcavity system, a plasma, or the like. In one specific implementation, the mode-locked laser can generate ultrashort optical pulses through periodic mode locking, which manifests as an equally spaced frequency comb in the frequency domain. In another specific implementation, the pumped microcavity system can include a pump laser and a microresonator. The pump laser can provide continuous or pulsed light input to the microresonator, which can convert the pump light into a broadband optical frequency comb. Plasma optical frequency combs generate frequency comb light by enhancing nonlinear effects (such as high harmonics and four-wave mixing) through surface plasmons in metal-dielectric nanostructures. The specific type of optical frequency comb light source 1 is not specifically limited in the embodiments of the present invention; any device capable of generating equally spaced multi-line optical signals falls within the scope of protection of the present invention.

[0041] like Figure 1 As shown, the output end of the spectrum splitter 2 is connected to the input end of the modulator array 3 to split the frequency comb optical signal output by the optical frequency comb light source 1 into multiple independent spectral lines.

[0042] In this embodiment, the spectrum splitter 2 is used to spatially separate the initial spectral lines of different frequencies in the frequency comb optical signal to form discrete spectral lines of each of the multiple initial spectral lines, so that each discrete spectral line can be modulated individually.

[0043] In a specific embodiment, the spectrum beam splitter 2 can be implemented using a wavelength-selective device such as a waveguide array grating or a diffraction grating. Based on the principles of light diffraction or interference, light of different frequencies or wavelengths can be separated by angle or path. For example, a diffraction grating, through the dispersion effect of light, causes light of different wavelengths to be emitted at different angles. Combined with a spatial optical path or waveguide structure, each discrete spectral line is guided into an independent channel. The spectrum beam splitter 2 is not specifically limited in the embodiments of the present invention.

[0044] like Figure 1 As shown, the output end of the modulator array 3 is connected to the input end of the spectrum combiner 4 to perform amplitude and phase modulation on each discrete spectrum line to obtain modulated spectrum lines of the plurality of discrete spectrum lines.

[0045] In this embodiment, the modulator array 3 is used to perform independent amplitude and phase modulation on each discrete spectral line after spatial separation to generate multiple modulated spectral lines carrying target waveform information.

[0046] In one embodiment, before amplitude and phase modulation, the light field The expression is ,in, 、 Represent the initial amplitude and phase of the ith discrete spectral line, where all discrete spectral lines are coherent. Each discrete spectral line corresponds to an independent modulation channel, and the modulator parameters are controlled in real time by an electrical signal (such as a digital signal from a control computer). The modulated light field for ,in, 、 The modulation of the amplitude and phase of each frequency component by the modulator array 3 is characterized respectively. The modulation of each discrete spectral line is precisely controlled by the modulator array 3. 、 , you can customize the frequency domain components of the synthesized target waveform.

[0047] like Figure 1 As shown, the output end of the spectrum combiner 4 is connected to the input end of the dispersion processing module 5 to combine multiple modulated spectrum lines to obtain a composite optical signal.

[0048] In this embodiment, the spectrum combiner 4 is used to combine the modulated multiple independent spectrum lines into a synthetic optical signal to achieve controllable coherent superposition of the light field.

[0049] In one specific embodiment, spectrum combiner 4 can utilize a device complementary to the spectrum beam splitter (e.g., a waveguide array grating, a reverse diffraction grating, etc.), utilizing the principle of optical interference to converge light of different frequencies along their original or symmetrical paths to the same output port. Spectrum combiner 4 is not specifically limited in the embodiments of the present invention.

[0050] In this specific embodiment, the combined optical signal is the coherent superposition of each modulated spectrum line, and its light field can be expressed as ,in, 、 represents the amplitude and phase of the modulated spectral line i. This signal is represented in the frequency domain as a comb spectrum carrying the target waveform information, which can provide frequency domain input for time domain waveform synthesis.

[0051] like Figure 1 As shown, the output end of the dispersion processing module 5 is connected to the input end of the photodetector array 6 to perform dispersion processing on the synthesized optical signal to generate a time domain optical signal.

[0052] In this embodiment, the dispersion processing module 5 processes the frequency-domain synthesized optical signal output by the spectrum combiner 4 to utilize its dispersion characteristics and adjust the time domain scale of the optical waveform to adapt to the bandwidth of the photodetector.

[0053] In a specific embodiment, the dispersion processing module 5 can be implemented using dispersion devices such as dispersion optical fibers, chirped fiber gratings, and the like. The dispersion processing module 5 is not specifically limited in the embodiment of the present invention.

[0054] In this specific embodiment, since the high-frequency optical signal propagates slowly (normal dispersion) or quickly (anomalous dispersion) in the dispersive medium, different frequency components produce different time delays. Ultimately, the frequency components are arranged in frequency order in the time domain and superimposed to form the target waveform.

[0055] like Figure 1 As shown, when the photodetector 6 receives the time-domain optical signal after dispersion processing, it converts the light intensity change into a current signal through the photoelectric effect to obtain a radio frequency electrical signal of the target waveform, and transmits the generated radio frequency arbitrary waveform to multiple control ports of the quantum chip as the driving signal required for quantum bit manipulation.

[0056] The optical frequency comb light source 1, spectrum beam splitter 2, modulator array 3, spectrum combiner 4, and dispersion processing module 5 are located in a room at room temperature. The photodetector 6 is housed in a low-temperature dilution refrigerator. The radio frequency electrical signal output by the signal generator is directly connected to the control interface of a quantum chip, such as a superconducting quantum chip or semiconductor chip, to drive the qubits to perform quantum gate operations or read their states.

[0057] Based on this, an embodiment of the present invention uses an optical frequency comb light source to generate multiple spectral lines with equal frequency intervals, and independently controls the amplitude and phase of each spectral line through a modulator array to achieve Fourier domain spectrum editing to generate high-frequency, large-bandwidth arbitrary waveforms, meeting the requirements of quantum bit manipulation for high-frequency, high-precision microwave signals.

[0058] Furthermore, in this embodiment, because optical fiber transmits signals with minimal phase shifts and simple relationships over a wide frequency and temperature range, this is highly advantageous for the development of advanced dispersion-based readout technologies. Furthermore, optical fiber's electromagnetic interference resistance—it neither radiates nor absorbs radio frequency signals—results in minimal crosstalk between channels, further facilitating high-precision, high-fidelity manipulation of quantum bits.

[0059] Figure 2 A schematic diagram of a signal generating device according to a specific embodiment of the present invention is shown.

[0060] like Figure 2 As shown, in this specific embodiment, the signal generating device further includes an optical beam splitter 7 and a plurality of photodetectors 6 .

[0061] The optical beam splitter 7 and multiple photodetectors 6 are simultaneously arranged inside the dilution refrigerator. The input end of the optical beam splitter 7 is connected to the output end of the dispersion processing module 5, and the output end of the optical beam splitter 7 is respectively connected to the input ends of the multiple photodetectors 6. In this specific embodiment, the time-domain optical signal is transmitted to the optical beam splitter 7 located inside the dilution refrigerator via a single optical fiber. The optical beam splitter 7 evenly splits the one-way time-domain optical signal into multiple-way time-domain optical signals in a low-temperature environment to achieve the conversion of a single optical signal into multiple-way synchronized optical signals. After the dispersion-processed time-domain optical signal is split into multiple channels by the optical beam splitter 7, the frequency component, phase relationship, and time-domain waveform of each time-domain optical signal are consistent with the waveform of the time-domain optical signal generated by the dispersion processing module 5. The multiple photodetectors 6 are used to convert the multiple-way time-domain optical signals into multiple-way radio frequency electrical signals to generate radio frequency arbitrary waveforms and output them to the quantum chip.

[0062] like Figure 2 As shown, in this specific embodiment, the signal generating device further includes an optical amplifier 8 .

[0063] The input of optical amplifier 8 can be connected to the output of dispersion processing module 5, and the output of optical amplifier 8 can be connected to the input of optical beam splitter 7 located within the dilution refrigerator. Optical amplifier 8 can be used to amplify the optical field of the time-domain optical signal output by dispersion processing module 5 to produce an amplified time-domain optical signal, thereby pre-compensating for the optical intensity loss caused by subsequent optical splitting. Optical beam splitter 7 is also used to split the amplified time-domain optical signal into multiple time-domain optical signals, which are transmitted to multiple photodetectors 6.

[0064] In one embodiment of the present invention, optical amplifier 8 can be configured as an adjustable optical amplifier, whose gain can be dynamically adjusted based on the number of paths in optical beam splitter 7 to compensate for splitting losses. For example, as the number of paths in optical beam splitter 7 increases, the gain of optical amplifier 8 can be adjusted upward to ensure that the power of each optical signal meets the sensitivity requirements of photodetector 6. The gain of the adjustable optical amplifier can be adjusted in real time via an external control signal to adapt to the dynamic requirements of the quantum chip measurement and control system.

[0065] Figure 3 FIG. 1 is a schematic diagram showing a signal generating device according to another specific embodiment of the present invention.

[0066] In this specific embodiment, the optical beam splitter 7 and the photodetector 6 can be integrated into the same packaging module, that is, Figure 3 The optoelectronic integrated module 9 shown in FIG has its input connected to the output of the optical amplifier 8, and its output connected to the control port of the quantum chip. Using this optoelectronic integrated module 9 can reduce the size of the signal generation device, facilitating high-density wiring within the dilution refrigerator.

[0067] Based on this, in an embodiment of the present invention, an optical beam splitter is arranged inside the dilution refrigerator to divide the single-path time-domain optical signal after dispersion processing into multiple paths. The frequency component, phase relationship, and time-domain waveform of each optical signal are consistent, which is suitable for multi-port parallel control of quantum chips, avoiding control errors caused by inconsistent transmission delays and amplitude attenuation of multiple signals.

[0068] Secondly, in the embodiment of the present invention, a single traditional coaxial cable can only transmit one electrical signal and has a diameter of several millimeters. However, since a single optical fiber can transmit multiple optical signals through wavelength division multiplexing, and the diameter of the optical fiber ( ) is only a few tens of times that of coaxial cable. Therefore, optical fiber can support high-density wiring. When the number of quantum bits expands to more than a hundred, the wiring volume of the optical fiber solution is significantly reduced compared to the cable solution, which can greatly alleviate the problem of insufficient space inside the refrigerator. In addition, because the weight per unit length of optical fiber is only ~70g / km, which is less than one ten-thousandth of the traditional coaxial cable (~600kg / km), the use of optical fiber can avoid problems such as excessive load on the internal structure of the refrigerator due to the weight of the cable. At the same time, the soft and bendable nature of optical fiber allows it to be flexibly inserted between the complex pipes inside the refrigerator, allowing for convenient and flexible wiring. There is no need to reserve turning space for rigid cables, thereby improving wiring efficiency. It is particularly suitable for the measurement and control of three-dimensional stacked quantum chip arrays.

[0069] Furthermore, because the loss of traditional solutions using cables to transmit RF signals increases rapidly with increasing frequency, taking a 20GHz signal as an example, the cable loss can reach ~3dB / m, while the optical fiber loss is only ~0.2dB / km, which is much lower than the cable loss. At the same time, because the optical fiber phase is insensitive to temperature changes and is adapted to low-temperature environments, the embodiments of the present invention transmit the time-domain optical signal to the low-temperature environment of the dilution refrigerator via optical fiber, which can reduce the thermal load of the dilution refrigerator.

[0070] Figure 4 A schematic diagram of a signal generating device including a spatial light modulator array according to a specific embodiment of the present invention is shown.

[0071] like Figure 4 As shown, in one specific embodiment, the modulator array 3 can use a spatial light modulator array as the modulation device, with each spatial light modulator corresponding to a discrete spectral line, independently controlling its amplitude and phase. In specific embodiments, the spatial light modulator can be implemented based on a liquid crystal modulator, an acousto-optic modulator, a microelectromechanical system (MEMS) modulator, a digital micromirror device (DMD), etc., to dynamically adjust the modulation parameters of each discrete spectral line.

[0072] In an embodiment of the present invention, the spatial light modulator can allow real-time and independent control of the amplitude and phase of each discrete spectral line through spatial light routing or wavelength multiplexing technology without the need for time-sharing processing, thereby improving modulation efficiency and obtaining a precise waveform.

[0073] Figure 5 A schematic diagram of a signal generating device including an amplitude modulator array and a phase modulator array according to a specific embodiment of the present invention is shown.

[0074] like Figure 5 As shown, in another specific embodiment, the modulator array 3 can also use an amplitude modulator array and a phase modulator array, wherein the amplitude modulator array and the phase modulator array can be cascaded to independently control the amplitude and phase of each spectral line. The cascade modulation composed of the amplitude modulator array and the phase modulator array can independently and precisely control each spectral line, obtaining the high-precision waveform required for quantum chip manipulation.

[0075] Figure 6 A schematic diagram of a signal generating device including a chip-integrated control array according to a specific embodiment of the present invention is shown.

[0076] like Figure 6 As shown, the signal generating device may include a chip integrated control array 10, wherein the chip integrated control array may be based on photonic integrated chip (PIC) technology, such as Figure 2The components shown in the figure, such as the spectrum splitter 2, the modulator array 3 and the spectrum combiner 4, are integrated on the same substrate (such as silicon or lithium niobate) to form a miniaturized, low-loss optical processing unit.

[0077] Figure 7 A schematic diagram of a signal generating device including a specific chip-integrated control array structure according to a specific embodiment of the present invention is shown.

[0078] like Figure 7 As shown, the frequency comb optical signal enters the input waveguide array grating included in the chip-integrated control array 10 from the optical frequency comb light source 1, and the frequency comb optical signal is separated into spectral lines of different wavelengths in the free input area. After amplitude and phase modulation are performed in sequence by the chip-based amplitude modulator array and the chip-based phase modulator array, the modulated spectral lines are recombined into a beam through the output waveguide array grating in the free output area to obtain a synthetic optical signal, which is transmitted to the dispersion processing module 5.

[0079] In this specific embodiment, since the optical path connection loss of traditional discrete optical devices such as spatial optical beam splitters and free-space modulators is relatively large, the optical path loss of the waveguide integration in the chip is extremely small in comparison, and the phase change caused by temperature drift is relatively small. Therefore, the chip-integrated control array 10 significantly improves signal stability and has a simple structure and a small size.

[0080] Figure 8 A schematic diagram of a signal generating device including an optical frequency comb module and an optical switch according to a specific embodiment of the present invention is shown.

[0081] like Figure 8 As shown, the optical frequency comb light source 1 can include multiple optical frequency comb modules and an optical switch. The output of each optical frequency comb module is connected to the input of the optical switch, which in turn is connected to the input of the spectrum splitter 2. Because each optical frequency comb module has a different central wavelength or frequency range, the generated frequency comb spectral lines have the same spacing but different overall frequency offsets. The optical switch can be used to rapidly switch between different optical frequency comb modules, enabling the system to dynamically select and output frequency comb optical signals within a specific frequency range.

[0082] Specifically, each optical frequency comb module can generate a spectrum with identically spaced frequency comb lines, while different optical frequency comb modules can generate different frequency comb line spacings. Therefore, by rapidly switching the optical switch, the signal generation device can generate RF waveforms in different frequency ranges after subsequent modulation and dispersion processing.

[0083] For example, Figure 8As shown, by switching the optical switch, spectrum 1 with a Gaussian distribution is input to spectrum beam splitter 2. After processing by modulator array 3, spectrum combiner 4, dispersion processing module 5, optical amplifier 8, optical beam splitter 7, and photodetector 6, a radio frequency signal as shown in output waveform 1 is generated. In another embodiment, by switching the optical switch, spectrum k with equally spaced and equal amplitude can also be input to spectrum beam splitter 2. After processing by modulator array 3, spectrum combiner 4, dispersion processing module 5, optical amplifier 8, optical beam splitter 7, and photodetector 6, a radio frequency signal as shown in output waveform K is generated.

[0084] Based on this, in an embodiment of the present invention, since a variety of complex RF waveforms need to be generated in different operation stages of the quantum chip, such as initialization, manipulation, reading, operation, error correction, etc., different optical frequency comb signals can be generated by switching the optical frequency comb module and adjusting the modulation parameters, so that the optical frequency comb light source can dynamically select the frequency range and reconstruct the RF signal waveform without replacing the hardware, realizing the function of dynamically reconfigurable arbitrary waveform generation, thereby adapting to the measurement and control requirements of multiple types of quantum bits and improving the measurement and control efficiency.

[0085] According to an embodiment of the present invention, Figures 1 to 8 The signal generating device shown may further include a control module, wherein the control module may be a field programmable gate array or a digital signal processor, etc., and may be used to coordinate parameter configuration and dynamic control of various components.

[0086] Specifically, the control module can Figures 1 to 3 The amplitude modulation coefficient and phase offset of the modulator array 3 shown in Figure 5 The modulation coefficient of the amplitude modulator array and the phase offset of the phase modulator array are respectively adjusted in real time to generate a target radio frequency signal of an arbitrary waveform in real time.

[0087] In addition, the control module can also receive host computer instructions or real-time feedback signals to generate optical switch switching pulse signals to achieve Figure 8 The rapid gating of multiple optical frequency comb modules shown in the figure makes it possible to dynamically generate multiple optical frequency comb signals on the same device by controlling the optical switch through the control module without replacing the hardware of the optical frequency comb light source. This reduces the system complexity and cost and improves compatibility while meeting the real-time frequency switching requirements in quantum measurement and control and supporting dynamic multi-frequency signal generation such as time-division multiplexing multi-channel measurement and control.

[0088] Figure 9 A flow chart of a signal generation method for a quantum chip measurement and control system according to an embodiment of the present invention is shown.

[0089] like Figure 9As shown, an embodiment of the present invention further proposes a signal generation method for a quantum chip measurement and control system, which includes operations S910 to S950.

[0090] In operation S910, a plurality of initial spectral lines included in the frequency comb optical signal are spatially separated to obtain a plurality of discrete spectral lines of the initial spectral lines with equal frequency intervals.

[0091] In operation S920, amplitude and phase modulation are performed on each discrete spectral line to obtain modulated spectral lines of the plurality of discrete spectral lines.

[0092] In operation S930, the multiple modulated spectral lines are combined to obtain a combined optical signal.

[0093] In operation S940, dispersion processing is performed on the synthesized optical signal to generate a time-domain optical signal through frequency-time mapping.

[0094] In operation S950 , the time-domain optical signal is converted into a radio frequency electrical signal to obtain a target radio frequency signal.

[0095] Among them, a signal generation method for a quantum chip measurement and control system also includes: amplifying a time-domain optical signal to obtain an amplified time-domain optical signal; introducing the amplified time-domain optical signal into a dilution refrigerator through an optical fiber to split the amplified time-domain optical signal into multiple time-domain optical signals; and converting the multiple time-domain optical signals into multiple radio frequency electrical signals to generate multiple radio frequency arbitrary waveforms.

[0096] Based on this, an embodiment of the present invention uses an optical frequency comb light source to generate multiple equally spaced frequency spectral lines, and independently controls the amplitude and phase of each spectral line through a modulator array to achieve Fourier domain spectrum editing, so as to generate high-frequency, large-bandwidth arbitrary waveforms, meeting the requirements of quantum bit manipulation for high-frequency, high-precision microwave signals.

[0097] Furthermore, in this embodiment, because optical fiber transmits signals with minimal phase shifts and simple relationships over a wide frequency and temperature range, this is highly advantageous for the development of advanced dispersion-based reading technologies. Furthermore, optical fiber's electromagnetic interference resistance—it neither radiates nor absorbs radio frequency signals—results in minimal crosstalk between channels. Combined with its wavelength division multiplexing capabilities, this technology is highly advantageous for high-precision, high-fidelity control of quantum chips in multi-channel signal transmission scenarios.

[0098] Secondly, in an embodiment of the present invention, an optical beam splitter is arranged inside the dilution refrigerator to divide the single-path time-domain optical signal after dispersion processing into multiple paths. The frequency component, phase relationship, and time-domain waveform of each optical signal are consistent, which is suitable for multi-port parallel control of quantum chips and avoids control errors caused by inconsistent transmission delays and amplitude attenuation of multiple signals.

[0099] In addition, in the embodiment of the present invention, a single traditional coaxial cable can only transmit one electrical signal and has a diameter of several millimeters. However, since a single optical fiber can transmit multiple optical signals through wavelength division multiplexing, and the diameter of the optical fiber ( ) is only a few tens of times that of coaxial cable. Therefore, optical fiber can support high-density wiring. When the number of quantum bits expands to more than a hundred, the wiring volume of the optical fiber solution is significantly smaller than that of the cable solution, which can greatly alleviate the problem of insufficient space inside the refrigerator. Because the weight per unit length of optical fiber is only ~70g / km, less than one ten-thousandth of traditional coaxial cable (~600kg / km), the use of optical fiber can avoid problems such as excessive load on the internal structure of the refrigerator caused by the weight of the cable. At the same time, the soft and flexible nature of optical fiber allows it to be flexibly inserted and inserted into the complex pipelines inside the refrigerator, allowing for convenient and flexible wiring. There is no need to reserve turning space for rigid cables, which can improve wiring efficiency and is particularly suitable for the measurement and control of three-dimensional stacked quantum chip arrays.

[0100] Furthermore, because the loss of traditional solutions using cables to transmit RF signals increases rapidly with increasing frequency, taking a 20GHz signal as an example, the cable loss can reach ~3dB / m, while the optical fiber loss is only ~0.2dB / km, which is much lower than the cable loss. At the same time, because the optical fiber phase is insensitive to temperature changes and is adapted to low-temperature environments, the embodiments of the present invention transmit the time-domain optical signal to the low-temperature environment of the dilution refrigerator via optical fiber, which can reduce the thermal load of the dilution refrigerator.

[0101] It should be noted that the signal generating method part in the embodiment of the present invention corresponds to the signal generating device part in the embodiment of the present invention. The description of the signal generating method part specifically refers to the signal generating device part, which will not be repeated here.

[0102] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes may occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, as well as the combination of boxes in the block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or may be implemented using a combination of dedicated hardware and computer instructions. It will be understood by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or coupled in various ways, even if such combinations or couplings are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention may be combined and / or coupled in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0103] The above describes embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A signal generating device for a quantum chip measurement and control system, characterized in that: The signal generating device comprises: An optical frequency comb light source for generating a frequency comb optical signal comprising a plurality of initial spectral lines with equal frequency intervals; a spectrum beam splitter, configured to spatially separate the plurality of initial spectrum lines included in the frequency comb optical signal to obtain discrete spectrum lines of the plurality of initial spectrum lines; A modulator array is used to perform amplitude and phase modulation on each of the discrete spectral lines to obtain modulated spectral lines of the plurality of discrete spectral lines, so as to meet the microwave signal requirements of quantum bit manipulation; A spectrum combiner, configured to combine the plurality of modulated spectrum lines to obtain a composite optical signal; a dispersion processing module configured to perform dispersion processing on the synthesized optical signal to adapt the time domain scale of the optical waveform to the bandwidth of the photodetector, and to arrange the frequency components in a frequency order in the time domain by controlling the time delay of different frequency components, superimposing them to achieve frequency-time mapping and generate a time domain optical signal; The signal generating device further includes an optical amplifier, which is used to amplify the time-domain optical signal to obtain an amplified time-domain optical signal to pre-compensate for the light intensity loss caused by subsequent light splitting, thereby ensuring that the power of each optical signal meets the sensitivity requirements of the photodetector; The signal generating device further includes an optical beam splitter and a plurality of the photodetectors, wherein the optical beam splitter and the plurality of the photodetectors are arranged inside the dilution refrigerator, and the amplified time-domain optical signal is transmitted to the optical beam splitter via an optical fiber; The optical beam splitter is used to split the amplified time domain optical signal into multiple time domain optical signals, wherein the waveform, frequency component, and phase relationship of each time domain optical signal are consistent with the waveform, frequency component, and phase relationship of the time domain optical signal generated by the dispersion processing module; The plurality of photoelectric detectors are used to convert the multiple time-domain optical signals into multiple radio frequency electrical signals to generate multiple target radio frequency signals; The control module is used to receive host computer instructions or real-time feedback signals, generate optical switch switching pulse signals, and adjust the amplitude modulation coefficient and phase offset of the modulator array in real time to generate a target RF signal with an arbitrary waveform in real time.

2. The signal generating device according to claim 1, wherein The modulator array includes a spatial light modulator array, and the spatial light modulator array is used to independently perform amplitude and phase modulation on each of the discrete spectral lines.

3. The signal generating device according to claim 1, wherein: The modulator array includes an amplitude modulator array and a phase modulator array; The amplitude modulator array is used to independently amplitude modulate each of the discrete spectral lines; The phase modulator array is configured to be cascaded with the amplitude modulator array, and the phase modulator is used to independently phase modulate each of the discrete spectral lines.

4. The signal generating device according to claim 1, wherein: The spectrum beam splitter, the modulator array and the spectrum combiner are integrated into a chip-type control array.

5. The signal generating device according to claim 4, characterized in that The spectrum beam splitter includes an input waveguide array grating, and the input waveguide array grating is used to spatially separate the multiple initial spectral lines included in the frequency comb optical signal to obtain discrete spectral lines of the multiple initial spectral lines; The modulator array includes an amplitude modulator array and a phase modulator array, and the amplitude modulator array and the phase modulator array are integrated on the chip-type control array to independently perform amplitude and phase modulation on each of the discrete spectral lines; The spectrum combiner includes an output waveguide array grating, which combines the multiple modulated spectrum lines to obtain the synthesized optical signal.

6. The signal generating device according to any one of claims 1 to 5, characterized in that: The optical frequency comb light source includes an optical frequency comb module and an optical switch; The optical frequency comb module is used to generate a plurality of frequency comb optical signals with different central wavelengths, and the optical switch is used to select different frequency comb optical signals.

7. A signal generation method for a quantum chip measurement and control system, applied to the signal generation device according to any one of claims 1 to 6, characterized in that: The signal generating method comprises: spatially separating a plurality of initial spectral lines with equal frequency intervals included in the frequency comb optical signal to obtain discrete spectral lines of the plurality of initial spectral lines; Performing amplitude and phase modulation on each of the discrete spectral lines to obtain modulated spectral lines of the plurality of discrete spectral lines; Combining the plurality of modulated spectral lines to obtain a composite optical signal; performing dispersion processing on the synthesized optical signal to generate a time-domain optical signal through frequency-time mapping; The time-domain optical signal is converted into a radio frequency electrical signal to obtain a target radio frequency signal.

8. The signal generating method according to claim 7, wherein: The method further comprises: amplifying the time-domain optical signal to obtain an amplified time-domain optical signal; introducing the amplified time-domain optical signal into a dilution refrigerator through an optical fiber, so as to split the amplified time-domain optical signal into multiple time-domain optical signals; The multiple time-domain optical signals are converted into multiple radio frequency electrical signals to generate multiple radio frequency arbitrary waveforms.

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